When a conspiracy ends, when the conspiracy has been defeated, what is the test for determining when it has ended?

"It is for the trier of fact -- considering the unique circumstances and the nature and purpose of the conspiracy of each case -- to determine precisely when the conspiracy has ended." (People v. Saling (1972) 7 Cal.3d 844, 852.) A conspiracy does not necessarily end merely because it is not carried out as originally planned. (See People v. Patrick (1981) 126 Cal.App.3d 952, 966 [kidnapping conspiracy was not defeated when police arrived; conspirators avoided defeat by pretending to abandon it, but resuming plan later].)