Season four of the hit ABC medical drama was on shaky ground from the season premiere, which left Cristina (Sandra Oh) at the altar by Burke (Isaiah Washington, fired after the press-frenzied third season); Meredith (Ellen Pompeo) and Derek (Patrick Dempsey) downgraded to no-relationship-just-sex status; and George (T.R. Knight) pondering divorce from Callie (Sara Ramirez) to pursue love with his best friend, Izzie (Katherine Heigl). That last pairing made for one of the worst decisions in the series thus far; George and Izzie always worked so well as friends without the will-they-won't-they element, but suddenly throwing them into bed and watching them fumble their way to coupledom (an attempt that mercifully doesn't last) was painful to watch, in particular because Heigl, who had won an Emmy for the previous season, was reduced to a lot of whining and fretting. Meanwhile, Meredith's family issues come to a head when her half-sister Lexie (Chyler Leigh) begins her internship at Seattle Grace and instantly tries too hard to bond. And as she once again drives away Derek with her trust issues, Meredith finally gets smart and enters therapy (one of the redeeming elements of the season, with Amy Madigan as the hard-nosed counselor) to "get healed." The writers' strike became a welcome blessing for the show, which had seriously derailed before its hiatus; during the strike, creator Shonda Rimes has said she reexamined the direction of the show, making for an ultimately satisfying second half of the season. Standout episodes include "Forever Young," in which a high school bus crash leaves the staff pontificating their own adolescent cliques; "Lay Your Hands on Me," with a standout performance by Chandra Wilson as Bailey, whose crumbling marriage comes front and center when her toddler gets in an accident; and the season finale "Freedom," in which Meredith and Derek save two brain-tumor patients in love (Jurnee Smollett and Marshall Allman), leading to their own (lasting?) reunion, Bailey heads up an effort to rescue a guy who lay in concrete to impress a girl; and Callie finds herself attracted to the new cardiac surgeon, Erica Hahn (Brooke Smith). --Ellen A. Kim