WARNING: The following article contains minor spoilers for The Rook, which premieres tonight on Starz.

Starz's new drama The Rook introduces a conspiracy set against the backdrop of a secret world of paranormal threats and conspiracies.

Based on the 2012 debut novel by Daniel O'Malley, The Rook follows Myfanwy Thomas, an operative for a British clandestine agency who suddenly finds herself in the middle of a mystery with no memory of who she is, or how she got there. The adaptation remains largely true to the source material, while toning down some of the supernatural elements -- sadly, the vampire Bishop Alrich is nowhere to be found on the television series -- and adding an American character.

Here's what you need to know about the world of The Rook, and its major players, as you settle in for the new thriller.

The Checquy

Rook: Episode 1

Britain's only truly secret service, the Checquy is a centuries-old organization is devoted to protecting the natural from extraordinary threats; in the novel those are explicitly supernatural, while on the Starz adaptation, they're of a more sci-fi nature.

RELATED: The Rook Adds Superpowers to a Generic Spy Drama

The agency's hierarchy is organized like chess pieces, with those with special powers, or Extreme Variant Abilities, in leadership positions. The King and Queen (referred to in the novel as Lord and Lady) are, of course, at the top, and Rooks overseeing domestic operations.

Myfanwy Thomas

The Rook: Myfanwy Thomas

Played by Emma Greenwell, Myfanwy (rhymes with "Tiffany") wakes up beside Millennium Bridge in London with no memory of who she is, or an explanation for the circle of dead bodies surrounding her. Her only clue begins with a note she Myfanwy left for herself in her coat pocket, addressed "To You," knowing her mind would be erased. She soon learns that she's a Rook employed by the Checquy who was targeted by an unknown assassin. The Starz miniseries, like O'Malley's novel, centers on Myfanwy's efforts to untangle the mystery.

The Myfanwy on Rook differs from that of the source material primarily in her superhuman ability: In the novel, she can control the bodies of others through touch, while in the adaptation she possesses some kind of bioelectric powers whose extent is unclear.

Gestalt

Rook: Gestalt

A hive mind, Gestalt is a single mind shared by four bodies, each with a different appearance and personality: Robert (Ronan Raftery), Eliza (Catherine Steadman) and identical twins Alex and Teddy (Jon Fletcher). However, they share every thought and experience, and sometimes speak as one, to unnerving effect.

Linda Farrier

Rook: Linda Farrier

The Checquy's current King (the titles aren't gender-specific), Linda Farrier is Myfanwy's mentor and trusted ally. It only takes King Farrier (Joely Richardson) a moment to realize Myfanwy isn't herself, and that she's responsible for the dead bodies that kick off Rook's central mystery.

In the novel, Farrier is able to enter and alter dreams, and use them to communicate with an individual. It's unclear whether she possesses the same power on the Starz drama.

Monica Reed

Rook: Monica Reed

Created for the television series, Monica Reed (Olivia Munn) is an operative for the U.S. Bureau of Variant Affairs, the Checquy's American counterpart. She's drawn to London by the mysterious incident at Millennium Bridge, whose victims include a former colleague and lover.

Conrad Grantchester

Rook: Conrad Grantchester

A Bishop in the novel, Conrad Grantchester (Adrian Lester) is elevated to Queen in the television drama. A deputy to Farrier, he begins to unravel the mystery surrounding Myfanwy even as he guards his own secrets.

Just as in the novel, Grantchester is able to manufacture chemical compounds in his body, and released them as a mist that takes different forms, from deadly toxins to tear gas to a dark cloud to disguise his activities.

Premiering today at 8 p.m. ET/PT on Starz, The Rook stars Emma Greenwell, Joely Richardson, Adrian Lester, Catherine Steadman, Jon Fletcher, Ronan Raftery and Olivia Munn. Encore presentations follow at 8:53 and 9:46.