unfinished business

Short definition from Wiktionary

Noun

1. 1
   A matter that still has to be completed or dealt with, sometimes with an ominous or threatening implication.
2. 2
   A matter that still has to be completed or dealt with, sometimes with an ominous or threatening implication: One or more things that a person intended or was destined to do in life, and cannot escape the earthly realm even after death until completed.