Lucas Mackey

"'The spreading of that contagion, or whatever the hell you want to call it, is the key...  I just know it.'"Lucas Mackey is an undercover agent for the United States Treasury Department. He appears many times and is one of the few allies in the game.

Role in the game
Mackey is first encountered when exiting the abandoned offices of the Innsmouth Courier. Mackey will walk towards Jack, calling him by his name. When asked by Jack how he knows his name, he will reply that in Innsmouth new names spread fast since there aren’t that many visitors. He will continue to ask questions about Burnham (implying that he is aware of Jack being a detective). He will then confirm that he is not from Innsmouth and will say he is just a government Factory Inspector, sent to investigate the Marsh Refinery.

After that he can be found walking in front of the entrance of the Marsh Refinery, saying that Jacob Marsh, the Refinery manager, didn’t show up to their appointment and that the Marshes never do. He can further be asked questions about the town and soon it will become clear he knows a lot. He genuinely believes that a plague was responsible for the huge deaths of 1846 and that the “Innsmouth look” is a manifestation of that disease.

While aware of the Order’s grasp over city and a connection between the "Innsmouth look" and suspicious activities by the Marshes, he seems to be unaware of their real power or their connection to the Deep Ones. He thinks that Robert Marsh is an evil man, obsessed with witchcraft, but doesn't consider the latter as a fact.

He can later be seen before and during the “Jailbreak” sequence, when he reveals his true motives (that of being an undercover agent) and how his department has been closely working for some time with the FBI, led by J. E. Hoover.

After Jack and Brian escape the town to save Ruth, Mackey will get captured by the Order and will be taken as a prisoner to the jail underneath the Esoteric Order. When met later, he doesn’t seem to have been physically or mentally hurt. After being freed up by Jack, he will accompany him (even using a gun) and help him get access to the Temple of Dagon.

He appears briefly at the end of the game when Jack comes out of a portal connecting Y’ha-nthlei with the building of the Esoteric Order.

Trivia

 * His face was supposedly modelled after H. P. Lovecraft ’s
 * He has a gun engraved with the name Mackey on it