Intros, time for next step?

I've been introducing the two male unaltered adult rats that I have remaining. They've been together for an hour with no blood drawn so far. Cass had flipped Klaus to show dominance but never hurts Klaus.

Time for the next step?

They'll be introduced next on my bed, although Cass wonders around the whole room and Klaus is too afraid to leave the bed.

this info might be helpful http://www.ratshackforum.com/forum/showthread.php?t=32368

I would do a couple of days, maybe three days on neutral ground and if no issues, then I'd move to general rat play area.