Alexander Skarsgård (Eric) previously promised that fans can expect a "bromance" between his character and Bill (Moyer).
"They've gotten themselves into a pretty dark situation," Moyer elaborated to Zap2it. "I think they decide that instead of fighting and being at each others' throats, that they'll get together and actually put their heads together."
Moyer added that he enjoys "playing [characters] against others" on the HBO paranormal drama.
"I think people like having favourites, and I think playing favourites against others, so... the more you give them, the more the chance there is of pleasing some of the [viewers] some of the time.
"I think [show exec] Alan [Ball]'s very clever. It's a funny, dark, twisted and amazing show. And it ticks a lot of boxes, I think."
It was recently revealed that former Buffy star James Marsters auditioned to play Skarsgård's vampire Eric Northman on True Blood.
The series returns for a fifth season on HBO on June 10 and on FX in the UK later this year.
> True Blood Alfre Woodard returning for season 5
Watch a trailer for the new season of True Blood below: