Danny Farrell’s newfound ability to spread promicin leads to several hundred deaths, including his mother. With Seattle in chaos, NTAC is forced to accept Promise City’s offer of help. Shawn is faced with a difficult decision when Danny asks him to end his life to stop the spread of promicin.
Isabelle works with Tom in order to get close to Jordan. Shawn recruits a small band of promicin positives to break Kevin out of Promise City. Tom and Diana face off in the backroom of a grocery store, and Diana is forced to shoot Tom.
A computer virus attacks a large software company owned by a suspected member of The Marked. Maia visits Promise City and receives an unexpected birthday gift.
The Director of National Intelligence pressures NTAC to pursue Richard and Isabelle. Richard is visited by his dead wife, Lily. Shawn and Kevin Burkhoff announce that they have developed a test that can tell people whether taking promicin will cause their death. Tom has a dream about the future and the 4400.
Richard kidnaps Isabelle from Collier’s Promise City. Richard hopes to start a new life with his daughter. Elsewhere, Tess has taken over a 1950’s diner, and Shawn is asked to intervene.
A lockdown at NTAC threatens the lives of Tom, Diana, Meghan, Shawn, Kyle, Jordan, Isabelle, Maia, Marco, PJ and Brady when they wakeup inside the building with no recollection of how they got there. They must work together to survive when he building appears to have a mind of its own.
Jordan and his followers annex a run-down part of Seattle, dubbing it “Promise City”. Shawn’s campaign for city council is threatened when a woman accuses him of using his healing ability in exchange for sex.