"Hard to explain," is all Billy can offer the others in that moment, expression pleading for Cassie especially to please just trust him on this.

"I told you I'd help you- all this time, I could've-" Billy's too frustrated to get a full thought out, whipping round in surprise at Cassie's warning.

He doesn't head Tommy's plea, in fact he does pretty much the polar opposite, taking off towards them in a blur to try and disarm them before anyone gets hurt.