Fifteen years ago, O, owner of Blackacre, an 80-acre parcel, executed and delivered a deed transferring 2 acres of Blackacre to X County. The relevant language of this deed stated: "O hereby grants 2 acres of Blackacre (adequately described) to X County to be used as the site of a highway weighing station. This deed is on the condition that if said use does not commence within 6 months from this date, or having commenced, ceases, the conveyance to be null and void." Ten years ago, O executed a deed to Blackacre and delivered it to David. This deed described Blackacre as it had been described in the deed by which O had acquired Blackacre. It made no mention of the deed to X County. Five years ago, O died intestate survived by Henry, his sole heir. The 2-acre parcel conveyed to X County was improved as a highway weighing station site within 60 days from the date of the first deed described above. It was continually used as such until last year when X County removed the weighing equipment and sold its interest in the land to Paul. David learned of the County's action before Paul took possession. David removed the fences which had separated the 2-acre parcel from David's land, and fenced around the outside boundaries of all of Blackacre so as to include the 2-acre parcel with his land. Who is now entitled to the 2-acre parcel and why?