The Tinfoil Dossier is a series of novels by Caitlin R. Kiernan that blend the Cthulhu Mythos with conspiratorial spy fiction, following the operations of the agents of shadowy quasi-governmental organizations as they battle (or in some cases assist) eldritch horrors. The series comprises Agents of Dreamland, Black Helicopters, and The Tindalos Asset.
Black Helicopters was first published as a chapbook by Subterranean Press in 2013, before Agents of Dreamland was published by Tor in 2017. But Tor published an expanded version of Black Helicopters in 2018, so it is designated the second book in the series, and Agents of Dreamland the first. The Tindalos Asset was published by Tor in 2020.
All three novels unfold achronologically, and involve events that occur over considerable stretches of time, but Black Helicopters takes place largely in 2012, Agents of Dreamland in 2015 and The Tindalos Asset in 2017.
Each book tells a self-contained story, but they are interlinked by the rival agencies that try to contain or exploit the outbreaks of unnatural horror that feature in the plots. These are:
- Albany, also known as Dreamland, a US-based organization that functions like the Men in Black or the FBI's X-Files program to neutralize or contain supernatural threats. The group has no official name, but is referred to as Albany because its headquarters are based in Albany, New York, beneath the Erastus Corning Tower.
- Barbican Estate, also known as Y, a London-based group that is sometimes a rival and sometimes an ally of Albany.
- X, a group with an affinity for chaos that is often an adversary of both Albany and Barbican Estate. They are sometimes referred to by the name of their leader, Julia Set.
Certain characters appear in more than one book, particularly The Signalman, an agent of Albany who appears in all three books. Other recurring characters include Julia Set and Barbican Estate's Immacolata Sexton.