The Second Key of the Architect was the key held by Grim Tuesday, until it was claimed by Lord Arthur . The Second Key grants control over the Far Reaches. The Second Key takes the form of two gauntlets made of flexible silver metal (when worn by Grim Tuesday and Lord Arthur; When Dame Primus became Steward of the Far Reaches, the gloves took on a more ladylike appearance to suit her)
The powers of the Second Key are numerous, and of such not all of them are known. The known powers of the Second Key are:
- Construction (creates objects out of Nothing)
- Telekinetic influence over objects
- Generation of protective fields
- Shedding light
- Commanding obediance
- Transforming objects
- Holding back/banishing Nothing
- A variety of other powers; such as small time reversals, accesing the Improbable Stair, levitation, etc. Along with all normal powers for a Key, which are almost unlimited.
As of Lady Friday it is said that all Keys can kill anything the wielder wishes, be it Nithling, Denizen, Superior Denizen or Mortal. It is beleived that any being not of those categories, such as The Architect, The Old One and their three children (Lord Sunday , The Mariner, and The Piper) would be unphased by any such attempts. Towards the end of the series, it is thought Lord Arthur would be immune as well. It is unknown if the Trustees were immune while wielding their Keys.