Bless Sam Worthington's little socks he does try. It's still a fascination of mine how this guy, Plainy McNoface himself, was the go-to guy for Hollywood a while back.
Heere he's completely outshone by Paul Bettany in what is a generally good show. There's one standout ep, that not so coincidentally does not include Worthington, and the rest is watchable if not extraordinary.
Just finished this myself and I've got to echo Taf's comments, Bettany was brilliant but what the hell were they thinking when they hired Worthington? He's so ridiculously bland, a complete non-entity. It's very good TV but it could have been great with the right casting.