Sarah Drew returns to for Thursday's two-hour season 18 finale, which also marks the long-running medical drama's milestone 400th episode, and she'll be alongside Jesse Williams for the special onscreen reunion. So what brings April and Jackson back to the hallowed halls of Grey Sloan Memorial Hospital? «Jackson is there representing the foundation and I am not entirely clear whether I work for the foundation now or not. But I'm there being a support and there's a lot of upheaval at the hospital, so Jackson is coming to try to sort out how to solve the upheaval and fix some of the issues,» Drew told ET's Cassie DiLaura over Zoom. While the actress remained tight-lipped about where April and Jackson currently stand in their relationship since the last time viewers saw them — in season 16, mainly to send off Williams -- Drew promised that they «share the screen» together.