Tracker brought back Jensen Ackles' character, Russell, in season 2 — and the Supernatural Easter eggs followed. During the newest episode, which aired on Sunday 20, Justin Hartley's character, Colter,

When Colter ( Justin Hartley) goes MIA while looking for a missing person, his team turns to his brother Russell ( Jensen Ackles) to help—and the episode adds to the Tracker mystery surrounding their father. (And yes, as with his first episode, there are plenty of moments that remind us of Ackles on Supernatural .)

Ackles plays the brother of Colton Shaw (Justin Hartley) in the CBS hit Sergei Bachlakov/CBS Jensen Ackles and Justin Hartley on Tracker Jensen Ackles' first Tracker episode of the season is sure to get Supernatural fans pretty revved up.

Tracker Season 2 is only two episodes deep, but the hit CBS show’s spectacular guest star streak is going strong. Season 2’s premiere let Manifest‘s Matt Long show his range, and the second episode of the sophomore season marks the moment Supernatural fans have been waiting for.

Jensen Ackles returns to play Russell Shaw on another episode of "Tracker," which finds the actor treading familiar territory rooted in sci-fi.

Season 2 of "Tracker," CBS's number 1 show, airs Sunday nights, and ET got an exclusive interview with star Justin Hartley and guest star Jensen Ackles. They dish about their 20-year friendship and what it's like working together for the first time.