Thus, in order to determine when the three conspiracies terminated, the court looked to the time when the substantive offense underlying each conspiracy was completed. (Id., at p. 554, fn. 12.) The court found that the central object of the conspiracy to commit grand theft was the 390*390 obtaining of insurance proceeds under false pretenses; hence, such conspiracy terminated upon the receipt of the last payment. (Id., at pp. 555, 560.)