“Dean... stop the car.” It wasn’t a suggestion, it was an order. Cas was... well, worried, but he was always worried about Dean these days. The Mark of Cain influenced bursts of... out-of-character darkness, anger, Cas wasn’t sure if he was just hyperaware of them or if they were actually getting stronger and more frequent. Dean’s driving wasn’t exactly an indication of anything being off, but still, at this speed, he’d crash the Impala before they reached the rogue angels.
Fully aware of how hesitant Dean was of letting anybody besides himself drive his car, Cas was determined to take the driver’s seat nevertheless. “I’m driving,” he stated. It wasn’t a question, he wasn’t asking for permission.
He was on edge himself. He had no particular interest in talking to any of his siblings. He was openly hated, Heaven’s Most Wanted, hunted down. For a good reason, he knew that, but it was... He was officially exiled, disowned. He had been exiled and disowned for a long time, really, but now that he had actually done things... awful enough to feel that he deserved to be, it felt different. But on edge or not, Cas was currently way more capable of doing the driving. He needed Dean to... calm down. Or they’d get themselves killed by the angels when they arrived... And more importantly, he needed Dean to calm down because the changes Cas could see and sense in him... frightened him. It... would end with him slowly losing Dean. If they let it get too far.