There's a trick about taking us in (4)
I believe the answer is:
ruse
'there's a trick' is the definition.
(I've seen this before)
'about taking us in' is the wordplay.
I cannot really understand how this works, but
'us' is within the answer.
'about' could be 're' ('re' means regarding or about) and 're' is found in the remaining letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ruse that I've seen before include "Sure to be a plot" , "Trick, stratagem" , "Subterfuge" , "Cunning plan" , "trick played" .)