There's a twist in the tales though as they're all set in the eighties, long before the contemporary events described in the novel. It's a ploy that works extremely well, not only establishing the history - the dark history - of the town but adding insight to the characters themselves, describing events that moulded and formed them, adding depth.
This is most effective in the opening story, The Sight, a story that's about as dark as it can get telling of the childhood horrors experienced by Alan and Vera, a tale of abuse and the abused which is unremittingly disturbing. It reminded me a lot of Joe Lansdale's Night They Missed the Horror Show, a story in which a dead dog being tied to the back of a car is the least horrible thing to happen in it. It's the strongest of the three stories and a powerful start to the collection.
The second story Gideon is the least effective of the three, using the trope of Hitch-hiker Given Sanctuary By Creepy Stranger to allow an exposition-heavy account of the history of Ash Fell in the post war years. It covers a lot of ground already explored in the novel but despite this is a nicely constructed, creepy story with some disturbing imagery.
How Briefly Dead Children Dream is the final story, the longest of the three, and tells of a battle between "The Shrike" - a wonderful creation, fusing human and supernatural evil - and two elderly residents of Kempforth over the souls (and bodies...) of two children. It's a thrilling end to the collection and even manages some moments of poignancy amidst the mayhem and horror.
It's not vital to have read The Faceless to appreciate these stories but I would recommend that you should read the novel before delving into them. (I'd recommend it anyway because it's a brilliant book). I'm not sure if they were written prior to, during or after the novel but they're a wonderful companion piece to it.
Disturbing and horrifying, Let's Drink to the Dead is another brilliant piece of writing from Simon Bestwick. Buy it you should, and you can do that here.