<P> The season picks up right where it left off at Owen and Amelia's wedding . After Alex Karev (Justin Chambers) had found a drunk Jo Wilson (Camilla Luddington) with Andrew DeLuca (Giacomo Gianniotti) in a compromising situation during the previous season's finale, he beats Andrew to a pulp, sending him to the hospital and subsequently landing Alex in jail . Alex is charged with a felony and is at risk of serving substantial jail time until Andrew drops the charges . Later, when Alex questions why Jo had turned down his proposal, she reveals that she is already married and has run away from her abusive husband . Meanwhile, Nathan Riggs (Martin Henderson) continues to pursue Meredith Grey (Ellen Pompeo) after their recent sexual encounter, though Meredith has trouble letting go of her late husband, Derek Shepherd . </P> <P> Maggie Pierce (Kelly McCreary) admits to Meredith that she has a crush on Nathan, unaware of Nathan and Meredith's blossoming relationship, and asks him out, only to be rejected . Maggie is later faced with a bigger issue when she discovers that her adoptive mother has cancer and has come to Grey - Sloan for treatment; her mother eventually passes away . April Kepner (Sarah Drew) and Jackson Avery (Jesse Williams) work together to co-parent their newborn daughter, Harriet, while maintaining a platonic relationship; however, they sleep together when they travel to Montana to perform a surgery . </P> <P> As Chief of Surgery, Miranda Bailey (Chandra Wilson) appoints Meredith as Head of General Surgery and hires Eliza Minnick (Marika Domińczyk) to run the training aspect of the hospital . Though Arizona Robbins (Jessica Capshaw) goes on to date Minnick, the rest of the staff widely opposes Minnick's teaching techniques and works to get her fired, only for Meredith to get temporarily suspended in the process . Richard Webber (James Pickens Jr .) and Catherine Avery (Debbie Allen) argue over Minnick's presence as well, making their marriage more divided than ever . Owen Hunt (Kevin McKidd) and Amelia Shepherd (Caterina Scorsone) also have marital issues after Amelia reveals that she doesn't want to have kids . This causes Amelia to move out and hide out at Stephanie's apartment . </P> <P> During the season finale, a rapist is admitted to the hospital and attempts to attack Stephanie Edwards (Jerrika Hinton) and a young girl . Stephanie starts a fire to escape the attacker, resulting in the entire hospital being destroyed . Owen's missing sister, Megan, is found and transported to Seattle; Meredith reveals this to Nathan and encourages him to return to Megan, whom he was engaged to before she was abducted . </P>

Who is chief in grey's anatomy season 13