Reeling from his kiss with Sienna, Brennan makes a quick exit from the house, grappling with guilt, his grief over Kate only compounded by this error in judgment. When pressed by Imogen about what she’s done to upset Brennan so much, Sienna lashes out and cuts Imogen down. Brennan finally returns home to tell Sienna their kiss was a terrible mistake and in order to avoid it ever happening agai... (thetvdb.com)