Oscar-winning director James Marsh has already proven himself a master at taking real stories and presenting them in equal parts fascinating and gripping ways with his documentaries Man On Wire and Project Nim. With Shadow Dancer he returns to feature length drama (after 2005’s The King) and the result is an admirable mixed bag.

Set in 1990s Belfast, the story follows MI5 agent Mac (Clive Owen) who convinces a vulnerable young member of the IRA, Collette (Angela Riseborough), to work for him and his agency to take down other IRA members. However, this is more complicated than he first realised as the IRA begins to suspect there is a mole and MI5 may have another mole planted whose identity is top secret.

Bolstered by wonderful performances from the likes of Owen, Gillian Anderson, Domhnall Gleeson and particularly rising star Riseborough as the woman conflicted between her long-standing beliefs and keeping her family safe, Shadow Dancer is a very well made film that’s very handsome to look at.

Unfortunately Marsh has chosen a deliberate pace that undermines rather than enhances the tension and drama, taking a potentially exciting film and making it feel slow and drawn out. That’s not to say a methodical pace can’t work for these types of thrillers, just look at the utterly fantastic Tinker Tailor Soldier Spy from last year, but here that pace sort of neuters the tension a lot of the time, suggestive of a more gripping film in there somewhere that’s hampered by not keeping things moving.

Having said that, Marsh is clearly a director who has a handle on the topics he chooses to deal with. Using a deft script by Tom Bradby (who also wrote the novel), he has constructed a film that deals with a difficult topic in a way that’s intriguing even if it’s not all that exciting in the moment. The plot is unpredictable, which is always a good thing, and the ending is just about perfect for the story being told. A denouement that’s completely satisfying even if the same can’t always be said about the journey there.

Shadow Dancer offers a vague, almost wishy-washy mentality that can sometimes feel frustrating, a kind of non-committal attitude that often leaves things feeling inert when they should hit you like a punch in the stomach. Nevertheless it has wonderful performances, looks beautiful and deals with tricky subject matter in an intelligent, grown up way. Certainly worth checking out but is ultimately more interesting than engaging.