Possible Clues:

• Probe small area inside old tunnel, perhaps
• Observe closely
• Study the hatchet back there along with my one
• Formally question (law)
• Test explosive device following cutback
• Former wife has a stock question
• Question cut-back by colliery
• Take a good look at the former underground workings
• Look closely and you'll find it was formerly underground
• Look well if one's no longer working down there