Ali Dawson, a cold case investigator with a secret ability to travel through time, is sent on her most dangerous mission yet: 1850s London. Tasked with clearing the name of Cain Templeton, a rumored member of the shadowy Collectors, Ali instead arrives to a fresh murder and a web of unanswered questions. As the investigation deepens, she becomes trapped in the past while her son, Finn, faces serious accusations in the present. With time running out and the two cases seemingly linked, Ali must uncover the truth before both their futures are lost.