The Mare's Nest is a 1964 book by English author David Irving, focusing on the German V-weapons campaign of 1944–45 and the Allied military and intelligence effort (Operation Crossbow) to counter it.

The book covers both sides of the story – the Allied arguments over how to interpret intelligence concerning the status and existence of the V-weapons and the German debate over how to deploy the new weapons to make the most of their supposed capacity to reverse the tide of the war.

[5] The Guardian's Clare Hollingworth noted that the book "provides some excellent quotations from intelligence documents, both British and German, as well as sketches of Peenemünde and of the [V-2 rocket]" and suggested that "perhaps scientists or soldiers engaged in rocketry" would find it useful.

He commended the author for having "successfully woven [his research] together into a coherent narrative, written in a brisk style", though he faulted Irving for having relied too heavily on Lord Cherwell's papers, with the result that he had treated "the problem as primarily one of scientific intelligence and [paid] insufficient attention to other more important aspects of the operation."

Nonetheless, Sandys concluded, "students will find in The Mare's Nest a mine of important information, while much wider circles will enjoy David Irving's vivid presentation of a strange story.

Even after Irving's reputation was destroyed after his exposure as a Holocaust denier,[10] Michael J. Neufeld of the Smithsonian's National Air and Space Museum has described The Mare's Nest as "the most complete account on both Allied and German sides of the V-weapons campaign in the last two years of the war.