Septimus really wasn't supposed to be here, but that hadn't stopped him before. The school term at Hogwarts had just started and already he'd been handed a sentence for punishment he didn't feel he deserved. The Potions Master was an unlearned twit who wouldn't know Sneezewort from Silverweed if his pathetic life depended on it. It wasn't like Sep was going to blow anything up, he just wanted to "enhance" his assignment with a few unlisted materials he'd found in the cupboards. He'd known what he was doing. But the lick-spittle professor reported him to the headmaster.
Now he was a free man. Though, at present he was a tad more free than was intended. Getting from the grounds to London had been tricky, but it wasn't the most daring adventure Septimus had ventured upon. Nor was this his first time in Knockturn alley.
Sep perused the shop windows along the alley. Perhaps he could find something nefarious enough to plant in the potion master's desk. A little turnabout was fair play, after all.