### Clue: Final entry in diary dated soon, Brexit primarily catastrophic (3,2,2,3)
### Answer: AND SO TO BED 
 ### Explanation: Definition: Final entry in diary
 **Anagram of**(… catastrophic) [DATED SOON + **the 1st letter of**(… primarily) "Brexit" ].
Defn: …, a diary that is traditionally filled at the end of the writer's day.