Once the camera pans over to Danger Mouse's starting position, you shall have to walk to the left, walk to the right up a staircase and throw a switch to activate the elevator; once you have done so, the game will automatically switch to Penfold as the elevator starts going up (but it will not go all the way).
While the elevator is ascending, you shall have to walk to its right side to avoid a broken wire, then back to its left side to avoid another broken wire and back to its right side to collect the first "DM" badge (if you miss it, you shall have to restart the level if you want to collect it); once you have done so, the game will automatically switch back to Danger Mouse as the elevator stops. You'll now have to jump up to two platforms in turn, kick a toad guard three times to kill him and collect the second "DM" badge - and once you have done so, you will have to jump up to a third platform and throw another switch.
The game shall now automatically switch back to Penfold as the elevator resumes its ascent; while it is doing so you shall have to walk to its left side to avoid a third broken wire, then back to its right one to avoid a fourth broken wire, back to its left one to avoid a fifth broken wire and back to its right one again to avoid a sixth broken wire. The game shall then automatically switch back to Danger Mouse again as the elevator stops for a second time - and you'll then have to: jump diagonally up to a fourth platform, walk up another staircase, jump up to a fifth platform, kick another toad guard three times to kill him and collect the third "DM" badge. Once you do so, you will have to jump up to a sixth platform, walk up a third staircase and throw a third switch.
The game will then automatically switch back to Penfold once again as the elevator resumes its ascent for a second time; as it is doing so you will have to collect the fourth "DM" badge, walk to its left side to avoid a seventh broken wire, then back to its right side to avoid an eighth broken wire, back to its left side again to collect the fifth "DM" badge, back to its right side again to avoid ninth broken wire, back to its left side once again to avoid tenth broken wire, back to the right side once again to avoid an eleventh broken wire, back to its left side yet again to avoid a twelfth broken wire and back to its right side yet again to collect the sixth "DM" badge (again, if you miss any of the badges, you shall have to restart the level, if you want to collect them); once you've done it, the game shall automatically switch back to Danger Mouse once again as the elevator stops for a third time. You shall now have to jump onto a vertically-moving platform, walk onto a seventh platform, and collect the seventh "DM" badge - and once you have done so you will have to jump up to an eighth platform and another vertically-moving platform in turn, walk onto a ninth platform and collect the eighth "DM" badge. Once you've done so, you'll have to walk back onto the second vertically-moving platform, jump up to a tenth platform and throw a fourth, last elevator-reactivating switch.
The game will automatically switch back to Penfold yet again as the elevator resumes its ascent for a third time; as it is doing so, you have to walk to its left side to avoid a thirteenth broken wire, then back to its right side to avoid a fourteenth broken wire, back to its left side again to collect the ninth "DM" badge, back to its right side again to avoid the fifteenth broken wire, and back to its left side again to avoid a sixteenth broken wire and collect the tenth "DM" badge (once again, if you miss either of these two, you shall have to restart the level if you wish to collect them). The game will now automatically switch back to Danger Mouse yet again as the elevator stops for a fourth time - and Stiletto will now fly down into view from the top of the screen to say "You never a-catch me, meester mouse! I'm a take da artifact to da big boss man! Ciao!". Danger Mouse will now say "Quick Penfold, after him!" as he flies back up off the top of the screen; you'll then have to walk back onto the second vertically-moving platform, jump up to three more platforms in turn and walk to the exit. Once you do so, you will have to switch back to Penfold and walk out of the elevator to the exit - and the "MISSION COMPLETE!" text shall then appear on the screen for a fourth time. The duo will then proceed onward to Episode 5, which features infinite-energy temple guardians.