Undaunted Puns

Not wanting anyone to be in danger, the town called in two investigators to check and see if the gas would be a hazard to the people nearby. The investigators took all their equipment and began to check if the gas would react to anything. They tested for common gases after taking small samples but none of them had a major presence. Undaunted the investigators pushed on and tried for rarer and rarer gases but found nothing. After hours and hours of checking and turning up no reactions, one investigator turned to the other and said, “Maybe the gasses are gone.”