Logline
An accident with an experimental quantum probability field causes everyone on the USS Enterprise to break uncontrollably into song, but the real danger is that the field is expanding and beginning to impact other ships—allies and enemies alike.
Written by Dana Horgan & Bill Wolkoff
Directed by Dermott Downs
They can both be seen in the corridors. The first one (in a red uniform) walks by Ortegas when the ship is hit by the energy field at the beginning. The other one (in a blue uniform) walks by Number One and Kirk during their song.
There may be more but those are the two that I spotted.