Clue: Variable working horror — cue to act over numbers initially on it? (4-4,8)
Answer: ZERO HOUR CONTRACT
Explanation: Definition: Variable working horror — cue to act over numbers initially on it?
not quite &lit, definition could be "Variable working…", or possibly "…it" referring back to the start of the surface
 **Z**="Variable", plus "working" as anagrind for (horror cue to act)*, around/"over" the initial letter of **N**[umbers]