Detective Bjorn interrupts brief vacation (6)
I believe the answer is:
holmes
'detective' is the definition.
(Sherlock Holmes)
'bjorn interrupts brief vacation' is the wordplay.
'bjorn' becomes 'me' (I can't justify this - if you can you should give a lot more credence to this answer).
'interrupts' means one lot of letters goes inside another.
'brief vacation' becomes 'hols' (short for holidays; 'brief' indicates an abbreviation).
'me' inserted within 'hols' is 'HOLMES'.
Can you help me to learn more?
(Other definitions for holmes that I've seen before include "Conan Doyle's 18" , "Famous detective" , "See 1 down" , "One good at interpreting clues" , "Conan Doyle creation" .)