A landowner contracted in writing to sell a lot to a brother and a sister, as joint tenants, for $60,000. The brother and the sister put up $6,000 as earnest money. Before the closing date, the landowner died. Shortly thereafter, and also before the closing date, a garage on the lot burned down. The garage had a fair market value of $6,500 and was a complete loss. After the fire, the brother demanded that the executor of the landowner's estate return the $6,000, because the brother and sister were no longer interested in the property. The executor refused and told the brother that he expected the brother and sister to tender the $54,000 due on the property when the closing date arrived. The brother and sister did not do so. The brother filed suit demanding a refund of the $6,000. The executor countersued, demanding specific performance by the brother and sister or, in the alternative, monetary damages. Absent any applicable statutes, how should the court rule