how does the Sertorius assassinazion work?

[hannibal128]

I have selected it a couple of times but nothing happened neither success nor failure was reported.

[PhilThib]

Double step and complex:

* When Sertorian morale is high (>100), the option becomes available
* If taken, it will work ONLY after Sertorian morale goes down below 100, and then there is a 10% chance per turn it happens