Time: 190 seconds
Once Leila and Albatross have reappeared on the screen (they will start this fourth stage with fifty bullets), start walking to the right as a Yellow Type 1 Masker drops down onto the ground from above and comes walking towards you; once you have fired a shot at him to kill him, a Green Type 2 Masker will jump down to the ground from above, and come walking towards you. Once you have fired two shots at him to kill him, you will have to jump over a box as another Yellow Type 1 Masker comes walking towards you, while firing bullets at you - and once you have fired a shot at him to kill him, a Silver Type 1 Masker will jump down to the ground from above and come walking towards you. Once you have fired shot at him to kill him, you will come to a door that's marked "BULLETS"; once you have entered this, you will gain 40 pistol bullets (which are indicated by the number that has appeared above the door going down to 0). Once you have come out of it, you will have to jump onto the first step of a platform that is made up of eight more boxes and eight oil drums (some of which are stacked on top of each other), as a second Silver Type 1 Masker drops down onto it from above and comes walking towards you - and once you have fired a shot at him to kill him, you will have to jump up onto the second step of this platform, as a Blue Type 1 Masker comes walking towards you. Once you have fired a shot at him to kill him, you'll have to drop down to the third step of this platform, as two more Yellow Type 1 Maskers jump down onto it from above and come walking towards you; once you have fired off shot at both of them to kill them, you will have to drop down to the ground as a Orange Type 2 Masker comes walking towards you while firing bullets at you. Once you have fired two shots at him to kill him, you will have to jump over a tenth box as the enormous circular door in the background (which has the Geldra organization logo on it) closes - and a fifth Yellow Type 2 Masker will then drop down to the ground from above and come walking towards you. Once you have fired a shot at him to kill him, you will come to another door that is marked "BULLETS"; once you have entered it, you will gain 40 more pistol bullets (again, they are indicated by the number that has appeared above the door going down to 0). Once you have come out of it, you will have to turn back to the left and jump back over the aforementioned tenth box as a fifth Yellow Type 1 Masker, another Green Type 2 Masker, and a Blue Type 2 Masker emerge from that aforementioned circular door and come walking towards you - and once you have fired a single shot at the Yellow Type 1 Masker to kill him and two shots at both of the Type 2 Masker to kill them, you will have to jump up to the platform on the aforementioned enormous circular door. Once you have done so, the screen will scroll upwards and the stage will continue (but as with the death of the first Barrier Man on the 2nd stage, you may have to wait a bit before it does).
You will now have to jump up to a balcony above as you end up on left side of an eleventh box and a third Green Type 2 Masker comes walking towards you; once you have fired two shots at him to kill him, you will have to jump up to a second balcony above. Once you have done so, a sixth Yellow Type 1 Masker and a fourth Green Type 2 Masker will drop down onto that aforementioned second balcony from above - and once you have fired off single shot at the Yellow Type 1 Masker to kill him and two shots at the Green Type 2 Masker to kill him, you'll have to jump over a twelfth box as another enormous circular door in the background (which, again, has that Geldra organization's logo on it) closes. Two more Green Type 2 Maskers, a second Blue Type 2 Masker and a second Orange Type 2 Masker will then emerge from that aforementioned second enormous circular door and come walking towards you; once you have fired off two shots at each of them to kill them, you will have to jump up to that platform on that aforementioned second enormous circular door. Once you have done it, the screen will scroll upwards again and the stage will continue again (but again, you may have to wait a bit before it does).
You will now have to jump up to a third balcony above, as seventh Green Type 2 Masker emerges from the second of the three doors upon it and comes walking towards you; once you have fired off two shots at him to kill him, two more Green Type 2 Maskers will emerge from the first and third doors upon the aforementioned third balcony, and come walking towards you from both sides. Once you have fired off two shots at both of them to kill them (but you will have to turn back to the left for the one that's emerged from the first door), you will have to jump up to a fourth balcony above as another Blue Type 1 Masker comes walking towards you - and once you have fired shot at him to kill him, third enormous circular door in that background (which, once again, has the Geldra organization's logo on it) will close up as two more Type 1 Maskers (one Yellow and one Silver) drop down onto the aforementioned third balcony from above and come walking towards you. Once you have fired off shot at both of them to kill them, two more Green Type 2 Maskers, a Purple Type 2 Masker, and a third Blue Type 2 Masker will emerge from that aforementioned third enormous circular door and come walking towards you; once you have fired two shots at each of them to kill them, you will have to jump up to the platform on that aforementioned third enormous circular door. Once you have done it, the screen will scroll upwards once again and the stage will continue once again (but again - you may have to wait a bit before it does).
You will now have to jump up to a fourth balcony above as a third Blue Type 1 Masker emerges from the door on it and comes walking towards you from behind; once you have turned back to the left, and fired a shot at him to kill him, an eighth Yellow Type 1 Masker will drop down onto the aforementioned fourth balcony from above, and come walking towards you from behind. Once you have fired off shot at him, to kill him, a fourth Silver Type 1 Masker will emerge from the second door on the aforementioned fourth balcony and come walking towards you - and once you have fired one shot at him to kill him, you will have to jump up to a fifth balcony above, as you come to a door that is marked "ARMS". Once you have entered it, you will gain 40 machine-gun bullets (once again, these are indicated by the number that has appeared above the door going down to 0); once you have come out of it, a ninth Yellow Type 1 Masker will drop down onto the aforementioned fifth balcony from above and come walking towards you. Once you have fired a shot at him to kill him, you will have to jump over three more boxes (the eleventh and twelfth of which are stacked on top of each other), before coming to two more boxes (the fourteenth of which, is on a sixth balcony above) - and once you have jumped over that thirteenth one, two more Green Type 2 Maskers will emerge from the two doors upon the aforementioned fifth balcony and come walking towards you. Once you have fired two shots at both of them to kill them, you will have to jump up to the aforementioned sixth balcony as a fourth Blue Type 1 Masker emerges from the door upon it and comes walking towards you; once you have fired a shot at him to kill him, two more Type 1 Maskers (one Yellow and one Blue) will emerge from the two doors on the aforementioned fifth balcony, and jump up to that aforementioned sixth balcony. Once you have fired shot at both of them to kill them, a fourteenth Green Type 2 Masker will emerge from the door on that aforementioned sixth balcony, and come walking towards you - and once you have fired off two shots at him to kill him, two more Type 1 Maskers (one Yellow and one Blue) will emerge from the two doors on the aforementioned fifth balcony and jump up to aforementioned sixth balcony. Once you have fired a shot at both of them to kill them, a third Blue Type 2 Masker will emerge from the door on that aforementioned sixth balcony and come walking towards you; once you have fired two shots at him to kill him two more Green Type 2 Maskers will emerge from the two doors on the aforementioned fifth balcony, and jump up to that aforementioned sixth balcony. Once you have fired two shots at both of these two to kill them, a seventh Blue Type 1 Masker will emerge from the door on the aforementioned sixth balcony, and come walking towards you - and once you have fired a shot at him to kill him, you have to drop back down to that aforementioned fifth balcony, and jump over three more boxes (the sixteenth and seventeenth of which are stacked on top of each other), as two more Green Type 2 Maskers come walking towards you. Once you have fired off two shots at both of them to kill them, two more Green Type 2 Maskers will emerge from two more doors on the aforementioned fifth balcony and come walking towards you - and once you have fired two shots at both of them to kill them, you will have to jump up to seventh balcony above you, as a fourth Blue Type 2 Masker emerges from the door on it and comes walking towards you. Once you have fired off two shots at this one to kill him a third Orange Type 2 Masker and another Purple Type 2 Masker will emerge from the two doors on the aforementioned fifth balcony, and jump up to the aforementioned seventh balcony; once you have fired two shots at both of these two, to kill them, a third Purple Type 2 Masker will emerge from the door on that aforementioned seventh balcony, and come walking towards you. Once you have fired two shots at him to kill him a twenty-first Green Type 2 Masker and a fourth Orange Type 2 Masker will emerge from the two doors on the aforementioned fifth balcony, and jump up to the aforementioned seventh balcony - and once you have fired two shots at both of them to kill them, a twenty-second Green Type 2 Masker will emerge from the door upon the aforementioned seventh balcony and come walking towards you. Once you have fired two shots at this one to kill him, a fourth Purple Type 2 Masker and a fifth Blue Type 2 Masker will emerge from the doors on the aforementioned fifth balcony, and jump up to the aforementioned seventh balcony; once you have fired two shots at both of them to kill them, a fifth Purple Type 2 Masker will emerge from that door upon that aforementioned seventh balcony, and come walking towards you. Once you have fired off two shots at this one to kill him, a fifth Orange Type 2 Masker and a twenty-third Green Type 2 Masker will emerge from the two doors upon the aforementioned fifth balcony and jump up to the aforementioned seventh balcony - and once you've fired off two shots at both of them to kill them, a sixth Blue Type 2 Masker will emerge from the door on the aforementioned seventh balcony, and come walking towards you. Once you have fired off two shots at him to kill him, two more Green Type 2 Maskers will emerge from the doors on the aforementioned fifth balcony, and jump up to the aforementioned seventh balcony; once you have fired two shots at both of them to kill them, a seventh Blue Type 2 Masker will emerge from the door on that aforementioned seventh balcony, and come walking towards you. Once you have fired two shots at him to kill him, sixth Orange Type 2 Masker and sixth Purple Type 2 Masker will emerge from the doors upon the aforementioned fifth balcony, and jump up to the aforementioned seventh balcony - and once you have fired two shots at both of these two, to kill them, a twenty-sixth Green Type 2 Masker will emerge from the door upon that aforementioned seventh balcony and come walking towards you. Once you have fired two shots at him to kill him, you will have to drop back down to the aforementioned fifth balcony again as a fifth Silver Type 1 Masker comes walking towards you; once you have fired off a shot at him to kill him, a seventh Orange Type 2 Masker will come walking towards you. Once you have fired off two shots at this one to kill him, two more Type 1 Maskers (one Silver and one Blue), will come walking towards you - and once you have fired off a shot at both of them to kill them, you will come to a third door that's marked "BULLETS". Once you have entered it, you will gain 40 more pistol bullets (yet again, they are indicated by the number that has appeared above the door going down to 0); once you have come out of it a twenty-seventh Green Type 2 Masker will come walking towards you. Once you have fired off two shots at him to kill him, you will have to jump over an eighteenth box - and once you have done so, the screen will scroll down (as opposed to up) and the stage will continue on.
You will now have to jump down to the aforementioned fourth balcony below as you end up on the right side of a nineteenth box; once you have jumped back over this, a twelfth Yellow Type 1 Masker and twenty-eighth Green Type 2 Masker will emerge from the two doors on it, and come walking towards you. Once you have fired two shots at both of them to kill them, you will have to jump down to the aforementioned third balcony below, as you end up on the right side of a twentieth box - and once you have jumped back over it, a seventh Silver Type 1 Masker will emerge from the third door on it and come walking towards you. Once you have fired off shot at him to kill him, you will have to jump down to the aforementioned second balcony below as you end up on the right side of a twenty-first box; once you have jumped back over this, thirteenth Yellow Type 1 Masker will emerge from that first door on it and come walking towards you. Once you have fired off a shot at him to kill him, you will have to jump down to the aforementioned first balcony below as you end up on the right side of a twenty-second box - and once you have jumped back over it, two more Silver Type 1 Maskers will emerge from the first and second doors on it and come walking towards you. Once you have fired a shot at both of them to kill them, you will have to jump down to the ground and continue walking to the right, as three more Yellow Type 1 Maskers come walking towards you; once you have fired off shot at each of them, to kill them, two more Type 1 Maskers (one Blue and one Silver) and twenty-ninth Green Type 2 Masker will drop down to the ground from above, and come walking towards you. Once you have fired off a singular shot at both of the Type 1 Maskers to kill them and two shots at the Green Type 2 Masker to kill him, two more Type 1 Maskers (one Silver and one Yellow) will drop down to the ground from above and come walking towards you - and once you have fired off a shot at both of them to kill them, an eleventh Silver Type 1 Masker (the last in the first half of the game) will come walking towards you. Once you have fired off shot at this last first-half Masker to kill him, the text "STAGE 4 CLEAR" will appear on the screen; you will then receive 10 bonus points for every second you have remaining, 50 points for every pistol bullet you have remaining and 100 points for every machine-gun bullet you have remaining (this is also the last stage in the game to feature doors marked "ARMS"). Leila and Albatross will then proceed to the fifth stage (in the country of Egypt) - which had previously been the setting for Konami Industry Co.'s Tutankham in 1982, along with the first stage of that same company's Koi no HotRock in 1986.