Callahan.

"Uncle served in the US Army before he moved to Cuba", Rehan says as we trudge along the corridor. "He earned a Purple Heart before leaving, even".

A Purple Heart?

I turn to him, genuinely surprised. "But he doesn't seem to be disabled. How did he get one?"

"He had to go for a heart surgery", he replies with a small frown. "The enemy bullet was lodged a couple of centimetres away from his heart, and he entered cardiac arrest almost immediately. Auntie was in tears for more than two months because of him".

Damn.

"That's where he got his knowledge of bombs?"

"Just a fraction. After he left the Army as a soldier he went back to university to learn about chemicals and all that. Wanted to make a difference- or so he says. I didn't know he meant it quite literally when he spoke about changing the world".

Hearing the murderous tone in his voice, I look up at Rehan, and there's an agonised expression on his face. "Rehan-"