"As long as you promise to only use it for responsible purposes," Rocket warns him, his lips pulled back in a toothy smile. "Like gettin' away safe, or scaring the pants off your friends."

With it only half-assembled, Rocket has to do very little to twist it open so Peter can see the inner workings. "See this part here, that's the bit that makes the big boom. You only wanna give it this much power though, or you can make the bigger kinda boom instead. Hook it in here, with the circuit, and this powder'll light up like an engine ignition at the same time. Poof."