This is the 12632nd most frequent Russian word.
контрразведке
"Counterintelligence."
Here, 'контрразведке' is in the prepositional case, used to indicate the place or area of work.
После обучения он начал работать в контрразведке.
After training, he started working in counterintelligence.
In this case, 'контрразведке' is in the dative case, showing to whom the help should be given.
Мы должны оказать всю возможную помощь контрразведке.
We must provide all possible support to the counterintelligence.
In this sentence, 'контрразведке' is in the dative case, indicating the indirect object of the action of being assigned.