Nels the Naughty is a nord barbarian and guest at Summitmist Manor in Skingrad. His daughter, Olga was killed by bandits during a raid on his village in Skyrim and the local garrison of the Imperial Legion did nothing to stop it making him regard soldiers like Neville as "useless, uncaring tools of corruption". He is one of the people invited to partake in the search for a hidden treasure within the manor.
After all the guest invited arrive at the Summitmist Manor the doors are locked and the guest are told they will not open until the treasure hidden in the manor is found. The one who finds it gets to keep all its contents. Unbeknownst to the guest there is no treasure and a member of the Dark Brotherhood walks among them slowly and secretly picking them off.
‘There were six on the night of last and then there were none... save one.’