Janowski is correct!
10a poisoned
Excellent, this was supposed to be difficult...
4d helpmate
5a Marshall
6d Hanstein
Correct on all three!
Here is the completed crossword:
Thanks yet again for an interesting puzzle.
I enjoyed making it too, but it never lasts more than a few hours with you, Zank, and others! Next time, it will be still more challenging...
Janowski is correct!