have (someone) at (one's) mercy

have (someone) at (one's) mercy

To have someone utterly under one's control, to the extent that one can force their actions. Please don't report me to the headmaster. You have me at your mercy! Once the gangsters were able to blackmail Susan, they had her at their mercy.

See also: have, mercy

have somebody at your ˈmercy

have somebody completely in your power or under your control: I’ve got you at my mercy now. What shall I do with you?

See also: have, mercy, somebody