Raising a family in The Unit (Fox; Monday to Friday at 10.40pm) is like living in a pressure cooker. Temperatures build and eventually, scalding jets of frustration need venting. For three seasons, we've watched Sergeant Jonas Blane (right; Dennis Haysbert; 24) and his fictional special forces team fly the coop for months on end on uber-cool, top-secret missions. And we've watched their wives struggle and stew on base in their absence. In its fourth and final season, The Unit experiences domestic terror(ism) that will clean blow the lid off of things. One can hardly blame the women, credited only as 'supporting characters' in their thanklessly muted and mundane roles, to want to stir up the pot for the big finale. To top it off, a ridiculously model-esque female operative takes aim at the team's chauvinist 'there are no women in the unit' credo. There are less obvious ways for a military drama to offset its testosterone but subtlety was never The Unit's strong suit. Snake Doctor, Dirt Diver, Betty Blue and Cool Breeze (to use the unit codenames) love their semi-automatics and grenades. Elsewhere, well-researched and thoughtful travel-documentary series Hidden Cities (The History Channel; Sundays at 10pm) approaches the history of four Asian countries through their forgotten palaces, temples and underground structures. In the first of four episodes, presenter Anthony Morse reveals that there's a lot more to Beijing than just the Forbidden City, as he explores the capital's best-kept secret - a series of cold-war bomb shelters. Morse tracks down 82-year-old Zhang Yimin, one of the shelters' chief engineers. The investigation eventually leads him to the neighbourhood of Nanluoguxiang, where he is joined by journalist Anthony Tao to take a look at a nuclear-bomb shelter before it's demolished. Next Morse heads to the Old Summer Palace; built in the 11th century, it was burnt down in 1860 by an invading Anglo-French army. He joins researchers from Tsinghua University, who have used 3D technology to virtually reconstruct the palace. Next, he also explores the tomb of a Ming dynasty (1368-1644) eunuch, called Tian Yi, which was hidden from public view until 1998. Morse also looks at Beijing during the Yuan dynasty (1279-1368), back when the city was a hub for Asia's religions. He ends his adventure by visiting the metropolis' oldest mosque and one of its oldest Buddhist temples.