Someone Who Is Present but Not Participating
This page is the CodyCross answer for the clue below from Train Travel, Group 708, Puzzle 3 (Flying Scotsman).
Question is: Someone Who Is Present but Not Participating
and the answer is: BYSTANDER
Word Meaning:
BYSTANDER — A person who, although present at some event, does not take part in it; an observer, witness, or spectator.
Definitions from Wiktionary.