Mom poked it with a pin, and out came some pus. The only trouble is that mom couldn't find the splinter and she didn't want to "dig" around in PlusOne's foot. Every night she looked at it, poked it, relieved the pus and couldn't find anything to pull out. Mom took PlusOne for his checkup and told the Doctor about it. He couldn't find anything when he looked at it with his light. So he told mom it would force itself out on its own and if it didn't, come back in a week.
A thorn. At least 3/8" long. It was difficult to get because of the way it was positioned, not across, but up and down in PlusOne's foot. The Doctor was amazed that he hadn't seen it the week before, but mom figures it was because of the way it was positioned.
He gave PlusOne a cup to take it home in and to show it off. It broke when PlusOne was showing it to memere. Mom says maybe PlusOne should wear his water shoes from now on. PlusOne agreed. He's a smart boy.