Bill and Ben are on course for imminent returns to the TV Series after new shots of them emerged online.
The China Clay Twins have together been absent from the show since the 11th Series episode Hector the Horrid, although Ben went onto appear in Season 12's Gordon Takes a Shortcut.
In an unknown Japanese book detailing characters on Sodor, the twins are presented in their CGI forms in new promotional shots.
Duck was teased to be in the 17th Series before he made a comeback in Henry's Hero.
The remaining 16 episodes are due for broadcast on the UK's Channel 5 milkshake! in October.