Phoenix from the Flame (I) - S5.E1

Relationships are challenged at Station 19 following Sullivan’s actions at Maya and Carina’s wedding, putting his marriage with Andy to the test. Dean comes to terms with his feelings for Vic, while Travis rekindles an old flame. The annual Phoenix Festival brings out some reckless behavior in some of Seattle’s citizens, challenging the teams at Station 19 and Grey Sloan Memorial.

The crossover continues on Grey's Anatomy S18E01 Here Comes the Sun (II).