Den of Thieves is a litany of undercooked ideas and missed potential but its biggest issue is the fact that it's a laborious slog. It wants to be a mix of Heat and The Usual Suspects but it’s not. Inside, and you get a glimpse of it every now and again, is an action-packed, potentially pretty decent 100-minute heist movie but what is served up is a 2 hour and 20-minute movie with too much filler - it’s right there but you can’t see the wood for the trees. The idea is a pretty good one.