Requiem ties up loose ends from previous installments and as Philip progresses he encounters various characters from his past. Penumbra: Requiem delves deeper into the world of the Tuurngait infection and personalities from the previous two games, Overture and Black Plague. Long lost friends return and aid Philip on his quest, but can they really be trusted? In the bizarre world of Penumbra: Requiem players experience another psychological thrill on a level unheard of before Penumbra: Black Plague. This time telling what is real and what is not is even harder and not always trusting your senses will be essential in order to survive.