### Clue: Turned up at home to score drug twice at beginning of night, just before half eleven (8)
### Answer: NINETEEN 
 ### Explanation: Definition: just before half eleven 
 **Reversal of**( Turned up, in a down clue) IN(at home) + NET(to score a goal, in games like football) E,E(twice the abbrev. for the drug Ecstasy) + **1st letter of**(beginning of) "night ".
Answer: The number just before twenty;half of the answer to 11 across. Nice misdirection, spelling out the clue number.