Doctor Who: ...ish

A conference of lexicographers: bromides in tweed. But the leading expert in the field is found dead by her own hand - and by her hologlyphic assistant. Is he responsible? Does the death fit any conventional definitions? Can the Doctor deduce who wrote the suicide note and why, exactly, it was riddled with spelling errors? Peri should help out, but there's a guy. Someone who loves language even more than the Doctor. Maybe, she realises, enough to kill for. Or perhaps just enough to ask her out to dinner. Unless, of course, he's already spoken for... Is it madness? Seeking transcendence in the complete lexicon? Having the right words on the tip of your tongue but never quite knowing when to use them? If so, how? ...ish