It involves the efforts of a similar think-tank, the Kamikaze Group, to uncover the secret of a rumored "super-weapon" Tesla had developed before his death, one supposedly responsible for the mysterious Tunguska explosion of 1908.

Feynman makes no claims for the tale's veracity, a caution warranted at the end of the book when his informant is revealed to have been pulp writer L. Ron Hubbard, a participant in the novel's events portrayed as a self-promoting, delusional narcissist.

Heinlein leads the fictional project, which also draws on the assistance of other pulp authors of his acquaintance, most notably Hubbard, Walter B. Gibson, and Lester Dent, with cameo roles by John W. Campbell, Norvell Page, Hugh B. Cave, Frederik Pohl, Cleve Cartmill, Kurt Vonnegut, Judith Merril, and Ray Bradbury.

Together with de Camp, Asimov, Hubbard and Gibson he explores a sub-basement of the Empire State Building where Tesla had left some of his equipment, and is almost trapped there by an unknown adversary.

Further inquiries take the core group to the former site of Wardenclyffe Tower, the inventor's wireless transmission facility in Shoreham, New York, which apparently doubled as the "sending" component of the weapon.

Afterwards Hubbard is sent first to the Aleutian Islands and then the South Pacific to retrieve the receiver, while Asimov is put in charge of securing the capacitors needed to make the transmitter work.

Meanwhile, government goons are investigating the group itself, alarmed by the publication of Cartmill's story "Deadline," with its all-too accurate description of a nuclear weapon similar to that being developed by the Manhattan Project.

Heinlein is disheartened to discover that his group was conceived and regarded as a mere blind to distract the Axis powers from the U.S.'s real super weapon effort—the Manhattan Project.

Nor are the big scenes - involving secret tunnels underneath the Empire State Building or the final showdown at Tesla's Tower - altogether fresh.

"[3] Paul Di Filippo in The Speculator "applaud[s] its vigorous storytelling and historical acumen," calling the book's style "by turns analytical, journalistic, affectionate, elegiac, philosophical, and, well, pulpish.

Di Filippo does twit the author for his anachronistic use of the term "sci-fi," not coined until the late 1950s, but feels that "[t]aken all in all, the book delivers both thrills and meditative reflections on the writerly condition.