Yes, you would need the original author's permission to finish their story and post it here.
It's not impossible for an author to return and finish even a long dead story and many take a dim view of anyone else getting there first.
LabRat :-)
Athos: If you'd told us what you were doing, we might have been able to plan this properly. Aramis: Yes, sorry. Athos: No, no, by all means, let's keep things suicidal.
