The end makes sense, it just wasn't explained clearly. It's how he first defeated the Cybus Cybermen. Craig hadn't actually been converted yet so he could hear his child screaming clearly. His emotions caused his cyber gear to malfunction (though I'll admit I don't understand why that caused it to crack open). Then (and yeah, this is sort of a guess as it wasn't explained clearly and it was a tad loud) Craig's gear, being the Cyber Controller, was connected to the other Cybermen, causing them to malfunction too...and their heads exploded...yeah, ok, it wasn't done well but the actual explanation behind it makes sense...I think.
Seriously, expected more from this forum XD Anyone have an opinion on the episode overall?

I loved it. Hilarious and terrifying.
Brief point to make that I forgot to include in Spoiler Alert; did the Doctor really just say "I've got an app for that"? Come on...
Oh, and I've figured out what the eyepatches are for. Haven't seen that anyone else has... Details in Spoiler Alert
