At the hospital, Cristina is shocked to hear Mere tell about the lion and doesn't seem to entirely believe it, and Mere is quite miffed. (For those who are curious, Mere saw animal control catch the lion with a tranquilizer and they took it away, so presumably we won't have a lion walking in to the ER and ripping the doctors to shreds. Although, you never can be too sure with this show...) Owen walks up to them to tell Mere that she is on his service, and his wife responds by walking away. He's much more interested in trying to talk to Mere about Cristina than about her lion sighting and Mere just tells him that he has to give Cristina time and let her come to him.
In a crowded elevator, Derek is also bragging about the lion and like his wife is put out that Mark is thinking about something else and barely listening. Mark is thinking about asking Julia to move in with him and wants more reassurance that Derek likes her, which we know he does. They then get off the elevator and a ton of people spill out as if it was a clown car until we can see that Lexie was standing in a back corner, heard everything, and is clearly not a fan of the idea of Mark's cohabitation.
So apparently the lion, who looked so calm while moseying through the intersection, did actually maul a couple of people and Jackson wants in on one of the cases. When he goes out to the ambulance bay he's surprised to see Richard, since Richard already had a scheduled surgery, but it turns out he traded that because he also wanted to work on a maulee. Of course he tries to tell Jackson he's just there to be, "of service to humankind," but Jackson sees right through it and so Richard switches gears and plays elder statesman, daring Jackson to even try and challenge him. When the ambulance arrives the patient they unload is Jonathan from Buffy, who is covered head to toe in claw marks and has one arm that was used as a chew toy. He's more worried about his girlfriend Naomi but the doctors don't really listen to him since they are each trying to take charge as well as get Mark and Callie to come help them out.