With Tracker losing three main cast members before season 3, there is potential for new - and even some familiar faces - to join Justin Hartley's show. Tracker, which debuted in 2024, introduced Us to survivalist Colter Shaw (Hartley) as he travels the country to help find missing people, track down information on criminal cases and more. The procedural quickly found success after being coined the most-watched broadcast premiere since NCIS' final episode with Mark Harmon in September 2021. Its average viewership was reported to be 18.