Olympia: The Age of Gods PBEM (May 4 1999)
When a noble dies and permanently ascends, his NPs are lost. The moral is to be careful not to let your nobles that have a lot of NPs invested in them be killed!
(In some variants, the ascension of a noble will return to the original player either 1 NP or the entire NP cost of the noble. Check the variant rules section for the particular game you are playing to see if these rules are in effect.)