This is a Lock (Optional 1)

 is an optional chamber in The Turing Test

Summary
This is a Lock is an achievement received after solving the optional puzzle located in Chapter 1, at the entrance to Sector 7.

Solving the puzzle unlocks an icy cavern containing the grave of Minos Brook, died December 24th, 2246.

Spoilers:
 * The solution to the lock is found in the lab at the end of Chapter 5.
 * Minos Brook is likely the name of Sarah Brook's child who died shortly after birth.
 * In Greek mythology, Europa is the mother of King Minos.