When last we saw the ludicrous Western Hell On Wheels (10 p.m. Saturday, AMC), a band of Mormons had ridden into town, shot the place up and taken Cullen Bohannon (Anson Mount) prisoner. They were about to hang him when, instead, he married the Mormon teen girl who is now carrying his child.And Season 4 of this increasingly crazy show picks up from there. It's unintentionally hilarious.Friday on TV ...Great Performances (8 p.m., PBS/Ch. 7): Gustavo Dudamel leads the Los Angeles Philharmonic in Verdi's "Requiem Mass" at the Hollywood Bowl.Crossbones (9 p.m., NBC/Ch. 5): Blackbeard sets sail as he puts his plans in motion.Saturday on TV ...MLS (7 p.m., ABC/Ch. 4): Real Salt Lake at Colorado RapidsPower (10 p.m., Starz): Ghost plans to hold a massive party at Truth in hopes of expanding out of NYC and the drug world.Sunday on TV ...Big Brother (7 p.m., CBS/Ch. 2): Nominations for eviction are revealed.Rising Star (7 p.m., ABC/Ch. 4): The quarterfinals begin.Last Tango in Halifax (7 p.m., PBS/Ch. 7): A surprise visitor makes Alan's day. (Season finale)The Musketeers (7 p.m., BBC America): The Musketeers investigate the tragic death of a young girl.The Last Ship (7 and 9 p.m., TNT): The crew receives a distress signal.Unforgettable (8 p.m., CBS/Ch. 2): A parolee Al helped put in jail is murdered.Masterpiece Mystery! (8 p.m., PBS/Ch. 7): "Poirot" continues with "Dead Man's Folly."The Lottery (8 p.m., Lifetime): Allison and James test Kyle and make a strange discovery.Falling Skies (8 and 10 p.m., TNT): Lexi becomes more powerful and ruthless.Reckless (9 p.m., CBS/Ch. 2): Roy agrees to represent his ex-wife's fiancé.Vicious (9:30 p.m., PBS/Ch. 7): Freddie and Stuart celebrate their anniversary. (Season finale)True Blood (10 p.m., HBO): Sookie is hoping for a miracle.Ray Donovan (10 p.m., Showtime): Ray tries to get a former member of Sully's gang out of the country.Halt and Catch Fire (11 p.m., AMC): In the Season 1 finale, Cameron takes her future into her own hands. (No word yet on a second season, but it's really iffy at this point.)The Strain (11 p.m., FX): Jim makes a startling confession; Ansel takes desperate measures to protect his family.The Leftovers (11 p.m., HBO): Nora goes to New York for the second annual Departure Related Occupations and Practices (DROP) conference.Masters of Sex (11 p.m., Showtime): Masters and Johnson are seen leaving a hotel together.