Take the Air from My Lungs

Derek keels over while Stiles is on the phone with Scott, and it only takes the teen a second to run to his side, realizing that Derek is suffering from a panic attack. Momentarily at a loss, Stiles runs through any grounding techniques he can think of while Derek's claws dig into the loft floor. Then he remembers what Lydia had said to him after kissing him to stop a panic attack in lieu of his father's kidnapping (Reference Season 3A), after she had kissed him. Derek's or the wolf inside Derek's reaction is far from expected, and the two seek Deaton's advice on what is happening.