The most serious and rigorously sourced book ever published on UAPs (Unidentified Anomalous Phenomena), Not For Disclosure reveals a hidden history that challenges everything we think we know.

For over fifty years, Jonathan Caplan KC has gathered extraordinary testimony from scientists, intelligence officers, politicians and military insiders across the world – assembling what may be the most comprehensive body of evidence yet of a reality long denied. When former US intelligence officer David Grusch testified under oath to Congress in 2023 that the United States possesses crashed non-human craft, global attention shifted overnight. But the full story has been kept from the public. Until now.

Caplan uncovers a pattern of secrecy stretching from covert Cold War programmes to alleged presidential briefings and clandestine recovery operations. Spanning sightings, encounters and abductions, and drawing on declassified documents, eyewitness testimony and insider claims, the book explores explosive allegations linking UAP knowledge to figures such as JFK, alongside newly revealed material on secret meetings involving Truman-era officials and the shadowy ‘Majestic 12’ group. Some who came close to the truth, Caplan suggests, paid the ultimate price.

Yet the most profound question remains: are these phenomena visitors – or something far closer, watching and interacting with us in ways we barely understand?

Meticulously researched, deeply unsettling and impossible to ignore, Not For Disclosure is a landmark work that pulls back the curtain on what could be the greatest cover-up in human history.

‘A very important book’ Talk TV

‘Caplan is one of the greatest legal minds in the world’ Daily Mail
‘Sceptics like me have no choice but to read this and decide if we ought to think again’ Jeffrey Archer

© Jonathan Caplan 2026 (P) Penguin Audio 2026