Wiktionary
do in
vb. (context transitive idiomatic English) To kill or end.
WordNet
do in
v. get rid of (someone who may be a threat) by killing; "The mafia liquidated the informer"; "the double agent was neutralized" [syn: neutralize, neutralise, liquidate, waste, knock off]
Usage examples of "do in".
But if she got to the others and told them what she knew, and if they believed, what might they do in order to escape the glamor in which they had been ensnared?
That was what he'd been trained to do in situations like this, and his training was correct.
Therefore, it is not unreasonable to postulate that whatever we do in the process of contacting them may result in severe culture shock.