Clue Cryptic with Herzwesten

Well, herzwesten and I are back on our bs (bud stuff), this time with a murder mystery, so don your deerstalkers and pack your pipes, gumshoes! Here's herzy: 

"I'm very excited for people to crack this case! It takes me back to a time when I used to edit logic puzzles professionally and in every issue we'd have a linked series of them all around a central mystery. The name of our fictional detective was Ivan Inkling, though sometimes his niece Anita Clew would take center stage. But don't worry, this puzzle doesn't contain nearly as many groan-inducing puns!"

Thanks as ever to the stalwart skaldskaparmal for his very helpful test.

(As with our text adventure cryptic, this puzzle makes use of the magic of spreadsheets.)

[solve online]