In this scene, the Doctor has set the TARDIS’ self-destruct system to activate in one hour — and we know he will let it blow, unless Clara can be found. But that won’t stop the Doctor from finding her — and pressing others into service.
By the way, those men are a salvage crew that mistakenly assumed the TARDIS was a junker and set about trying to strip it for salvage. But the Doctor (Matt Smith) would never let happen to his beloved machine.
The clock is ticking, and now everyone’s life is on the line!