Half-Life/Pre-Black Mesa

Timeline

 * March 3rd, 200*: The G-man is spotted in the Santego Military Base in Arizona, at which Corporal Adrian Shephard’s Hazardous Environment Combat Unit is training.
 * March 9th, 200*: Adrian’s unit is suddenly assigned to extensive Indoor Strategic Combat Training.
 * March 15th, 200*: A future mission involving Black Mesa is confirmed for the marines in Santego, although no other details are given. They put on a continuous alert, as the date at which the mission will occur is unknown, and could be at any time.
 * May 5th, 200*: After a recommendation from Dr. Isaac Kleiner, Gordon Freeman is made an official Black Mesa employee via a letter from “lm” and the Office of the Administrator (OTA). Gordon is asked to arrive for work no later than May 15th.
 * May 9th, 200*: Barney Calhoun receives a Memorandum from “lm” of the OTA (CC: Dr. Kleiner), informing him that the OTA has reassigned him to the Blue Shift in the Anomalous Materials Laboratories of Sector C Area 3. He is told to report to Black Mesa Personnel for processing of his increase to Salary Class A and verification of his retinal scan before May 12th. He will begin his first 13-hour workday of the 3-month-long assignment to Blue Shift at 09:00 on May 15th, 200*
 * May 11th, 200*: “lm” of the OTA sends a memo to Dr. Colette Green, notifying her that the crystal sample (EP-0021) about to be tested in the Test Chamber will be replaced with the far more pure and unstable specimen (GG-3883) retrieved from Xen by survey team “GG”. “lm” also orders the experiment to be done as quickly as possible, in spite of proper procedure. No explanation is given as to why.
 * 08:00 May 12th, 200*: Barney Calhoun is scheduled to go through the Hazard Course as part of a two-day training course that will prepare him for assignment to high-security areas. He is instructed by a holographic recording of a security guard named Miller.