Highlander: The Raven (1998)

S1E5 So Shall Ye Reap

While working on an agricultural initiative, a scientist is murdered, revealing he is the son of Charlie, an elderly man who once knew Amanda and discovered her Immortal nature in the 1960s. Back then, Charlie was a spy. Convinced his son was a victim of foul play, Charlie seeks Amanda's help, enlisting Nick to uncover the truth. They soon discover the scientist’s death is part of a series of mysterious fatalities among project team members. With federal agents pursuing them, they learn of a government scheme to produce estrogen-infused wheat seeds designed to incapacitate enemy nations. To protect themselves, Nick and Amanda leak the information to the press, but the lead agent responsible for Charlie's son's death is acquitted. In a tragic turn, Charlie avenges his son, sacrificing himself in the process, leaving Amanda to grieve alone.