What can you say when you have used many possibilities, but there is still one available solution that people are not usually expecting?
In PIV/Vortaro.net, there is
truk/o
- 1 Artifiko uzata en filmado, por doni la aspekton de realeco al dekoracio ks.
- 2 (f) Ĉia lertaĵo aŭ artifiko.
but I am not sure if this word is suited, because here the "trick" is not a way to hide truth nor to give the impression of truth.