Dead Space: Apocalypse

After the events of Tau Volantis and the Bretheren Moons, Isaac Clarke and John Carver separate. John moved to Gliese, a luxurious planet, and Isaac lives on the Heliopause Observer space station, protesting against Unitiologist activities. One day, Isaac receives a transmission from a planet called Markeeus. It states the Planet is the REAL Marker source. He immediately calls John