A leather case causes some doubts!

Leather case made in naturally tanned leather by FG
Natalia´s leather case as made by FG

I was going to entitle this post, ‘Fernando gets back on the case’ (after his birthday celebrations) and then (as you do) thought I’d just check out that colloquialism on google. Only one idiom came up, ‘ to get on sb´s case’ ie. to annoy or nag somebody for something they´ve done. But can´t you say ‘to get on the case’ to mean ‘to look into something or to start on a project to get something done? I thought and looked some more and found this headline in the Guardian newspaper… ‘Why won´t Air Canada get on the case of my missing luggage?’

That´s the meaning I wanted (and with a little play on words thrown in!)