Clockwork owl

A clockwork owl was a valuable artifact owned by Maurice Newbury (COMIC: The Undying) and Archibald Angelchrist. (PROSE: Paradox Lost)

In 1903, the owl was present at Maurice Newbury's home at Cleveland Avenue. (COMIC: The Undying)

By 1910, Angelchrist was in possession of the owl and the Eleventh Doctor studied it in his laboratory. Angelchrist claimed that he it was given to him by a dear friend. (PROSE: Paradox Lost) At some point Newbury regained possession of the owl. (PROSE: Ghosts of Empire)

Behind the scenes
The clockwork owl first appeared in Mann's 2009 Newbury & Hobbes novel The Osiris Ritual. At this point the owl belonged to Maurice Newbury, and would later be seen again as one of Newbury's possession in The Undying comic a decade later. The short story The Shattered Teacup, collected in The Casebook of Newbury & Hobbes, told the story of Newbury's acquisition of the owl from a Lord Carruthers. The NSA novel Paradox Lost introduced Archibald Angelchrist and presented him as the owl's owner with it being given to him years earlier by an "old and very dear friend".