Shadows of Doubt was a P.R.O.B.E. webcast first released in 2020 via YouTube. It was the first story released in the series since 2015's When to Die, just over five years prior. It also featured the return of Giles from that story, now serving as director of the organisation.
- Writer - Hunter O'Connell, James Wylder, James Hornby
- Initial concept - Aristide Twain
- Editing - Callum Brown
- It has been five years since Giles took over the Preternatural Research Bureau. Haggard put him in charge.
- Tasha, Maxie, Agamya, and As are members of PROBE. Giles worries that they might not be able to face the perihelion. Giles lost someone called Archie.
- This story marks the first webcast in the P.R.O.B.E. series. All prior releases had been either direct-to-VHS or direct-to-DVD.
- This story also marks the first in the series to be produced by Arcbeatle Press and is therefore also the first not released by BBV Productions.
- This is the first entry in the P.R.O.B.E. series not to feature, nor mention, Liz Shaw.
- The reservoir of evil is once again becoming a threat due to the upcoming perihelion. (HOMEVID: The Zero Imperative)
- Giles mentions Patsy Haggard. (HOMEVID: The Zero Imperative, etc.)