Collider argues that Tracker’s fourth season will need to bring back Jensen Ackles’s Russell Shaw to resolve its central family mystery. The Season 3 finale left Russell holding evidence that may reveal whether their father, Ashton, subjected Colter Shaw to childhood experiments, making his absence crucial to the show’s main storyline rather than a routine guest-character departure.

Russell, a former soldier and Horizon Group security contractor, became more deeply involved in Season 3 as he and Colter investigated The Process and the Chrono Stasis programme. They uncovered links between Ashton and covert experiments on gifted children, helped rescue two test subjects, and then Russell received a file about Colter; he reportedly agreed to undertake another job in exchange for the evidence disappearing, while asking Reenie to keep Colter from finding him.