There is the following sentence in the scene Director of FBI, H.A.L Tyson instructs his men in Jeffery Archer’s fiction, “Shall we tell the President”:
“So they (assassins group) think you’re dead, Andrews, and they have now played their last card. So we must hold ours back, you’re going to remain dead – for a little while longer”
Mark (Andrews) and O’Malley (both FBI agents) looked at each other, both puzzled. - Page 296.
I lightly took “hold one’s back” for a run-of-the mill idiom, but I couldn’t find this phrase in any of Cambridge, Oxford, and Merrimu Webster Dictionary as an idiom, nor does Google NGram Viewer include.
What does “We must hold ours back” mean? Isn’t “Hold one’s back” a common idiom?