N.H. Rev. Stat. Ann. § 303:14

If the land or rights sold shall not be redeemed within one year from the day of sale, the collector shall execute to the purchaser a good and valid deed of conveyance thereof; but no such deed shall be executed until the time of redemption has expired. If any proprietors' collector shall die, remove from the state or in any way be rendered incapable of completing the duty of his office, his successors respectively may complete the same.