### Clue: Difficult issue for Ashmolean – I'm beginning to discover cracks (5,2,1,7)
### Answer: HORNS OF A DILEMMA 
 ### Explanation: Definition: Difficult issue
An anagram ('cracks') of 'for Ashmolean I'm' plus D ('beginning to **D**iscover'). In the surface, the Ashmolean is a museum in Oxford.