Tonight's TV highlights are led by the return of "Colin from Accounts" for its final series on BBC One, alongside a Channel 4 documentary revisiting the September 11 attacks and a mix of factual, drama and quiz programming across the schedule.

The Australian romcom returns three years after Gordon's botched proposal, with both leads now in unsatisfying relationships and a chance reunion reigniting old feelings; critics praise the continued chemistry between real-life couple Patrick Brammall and Harriet Dyer. Elsewhere, Channel 4's 9/11 documentary examines newly released documents implicating Omar al-Bayoumi and alleged Saudi government links, which he and Saudi Arabia deny, while other picks include Fred Sirieix touring a South African safari lodge, a murder mystery in "Ludwig"-style drama, University Challenge featuring Birmingham and Leicester, a new true-crime series on 999 call aftermaths, and the 1959 film classic "Imitation of Life" on Film4.