The specific performance of a contract is the actual execution of the contract according to its stipulations and terms, and the courts direct the party in default to do the very thing which he contracted to do. The stipulations and terms of the contract have, therefore, to be certain and the parties must have been consensus ad idem. The burden of showing the stipulations and terms of the contract and that the minds were ad idem is, of course, on the plaintiff. If the stipulations and terms are uncertain, and the parties are not ad idem, there can be no specific performance, for there was no contract at all. [Para 18]