### Clue: Implore conservationists to step in before soldiers return (7)
### Answer: ENTREAT 
 ### Explanation: Definition: Implore
 NT(abbrev. for the National Trust, an organisation concerned with the conservation of historic buildings, monuments, and countryside) **contained in**(to step in) ERE(poetic form of "before") +** reversal of**(… return) TA(abbrev. for the Territorial Army of volunteer soldiers).