finger in the pie

finger in the pie также finger in every pie  {n. phr.},  {informal}

Причастность к происходящему; частичная заинтересованность или ответственность.

When the girls got up a Christmas party, I felt sure Alice had a finger in the pie.

The Jones Company was chosen to build the new hospital and we knew Mr. Smith had a finger in the pie.

Jack is a boy with a finger in every pie at school, from dramatics to football.

Ср.: HAVE A HAND IN, TOO MANY IRONS IN THE FIRE.