A contract validly formed lapses if one of its essential elements disappears.
Where the performance of several contracts is necessary for the performance of the same transaction and one of them disappears, contracts whose performance is rendered impossible by that disappearance and those for which the performance of the disappeared contract was a determining condition of a party’s consent lapse.
Lapse occurs, however, only if the contracting party against whom it is invoked was aware of the existence of the overall transaction when he gave his consent.