Disclaimer: I do not own Harry Potter. I wish I did! I am just borrowing Lily and Sev and the others to have a little fun with them. Enjoy!

Revised as of 11/08/11

I can't believe the amount of editing this required- punctuation mistakes and misspellings. Watch out for the sequel shortly- "The Forfeit".

The Challenge

Severus Snape set down his Potions utensils. He was first in the Potions classroom as usual. He pulled out his Potions book and mused over what Slughorn would set the class today. Hopefully it would prove to be more of a challenge then the last few assignments. Slughorn was more concerned with his comforts and his contacts than teaching. As he was musing over the inadequacies of his instructor suddenly Severus felt a pair of hands cover his eyes. He had instinctively drawn his wand but he quickly relented. Only Lily Evans would dare come up behind him and risk him hexing her.

"Miss Evans, can you please refrain from silly games?" He imitated the jovial voice of Horace Slughorn. She grinned.

"That's two hundred points from Gryffindor," he added wickedly.

"Hey Slughorn would never take points away from me," she said indignantly, removing her hands and sitting down on the chair next to him. No probably not.

"Point taken Lil! Teacher's pet.."

"I am not. I'm just smart."

Severus just smirked at his best friend and raised his eyebrows incredulously.

"I could get him to take points if I wanted!" she insisted emphatically, as she began laying out her Potions kit.

"Want to bet?"

"How about the loser has to wear the other's scarf to the Quidditch match next Saturday." she said grinning wickedly. Severus looked at her sceptically.

"Fair enough," he agreed. "For the record I do think that the silver and green will set off your eyes nicely".

She laughed, but added "I'll prove you wrong you know."

"What do you mean? The scarf or the bet?" he retorted sardonically. She rolled her eyes.

The classroom was quickly filling up as the other Slytherins and Gryffindors entered. Severus could see that Lily was thinking hard on a way to lose points. No way. There was no way she would do anything bad enough to lose points for her beloved Gryffindor. Although.. He could see Potter out of the corner of his eye sending him evil looks. He turned to Lily and whispered in her ear.

"Lily, if you are still intent on humiliating me then you might consider Potter as a target. At least then I would have that."

Lily had that dangerous glint in her eye that he was so familiar with. Good. If he was to lose this bet then at least Potter might suffer. In fact it would be almost worth it but not quite...

"Well, well," came the voice of Slughorn as he entered the room from his stores. The rest of the class were hastily placing their things on the table as Slughorn announced that their assignment for the day was Swelling Solution. Severus caught Lily's eye and they both erupted in gales of laughter. Severus had plenty ideas for mischief considering the nature of the potion involved. Slughorn looked at the two quizzically.

"Sorry Professor," said Lily in her most ingratiating voice.

"No harm done dear. I am just glad to see students enjoying my class. Now see page 151 for the instructions. You may begin now."

"See," Severus hissed, "you just can't help yourself!".

Lily poked him hard in the ribs with her elbow and he almost fell out of his chair. Lily giggled again and Severus' lip twitched once more. There were nasty looks coming from both Slytherins and Gryffindors. They all disproved of their friendship. Slytherins and Gryffindors simply should not be friends.

"What does she see in that slimy greaseball?" Potter's arrogant voice carried across the room to Snape's ears.

"Lily," he whispered, "I know I said that you should spill some swelling solution on Potter but seeing as his head is already swollen perhaps you ought to spill it on someone else because he has this amazing ability to keep his balance despite his abnormally large head."

Her lip twitched. "Shut up and stop making me laugh. Get on with the Potion."

Severus set about cutting his ingredients with precision silently wondering whether Lily would have the guts to go through with this challenge. They worked in silence side by side overseen by Slughorn who was happily sucking on crystallised pineapple at his desk.

Both Lily and Severus were finished making their potions before the rest of the class as usual. Severus wondered if Lily had chickened out when Slughorn headed over to their table.

"Lily, Severus, seeing as you both are finished your potion, would you can help out the less gifted in the class. Lily, could you help Mr Potter and Mr Black? Severus, Mr Mulciber and Mr Avery's potions needs some tweaking. Points for your respective houses if you manage to turn around their fortunes." He bounded away cheerfully and Severus headed over to his fellow Housemates.

Severus could see immediately the problems with the two boys potions.

"What do you see in that mudblood? You would want to watch your place."

Perhaps they should learn how to read was the first thought that struck him.

"That second line says 'add the root before stirring!'" he informed them.

"Seriously, Snape, you get a hard enough time as it is being a half blood." interrupted Mulciber, "Hanging out with that is just asking for trouble."

"Maybe, but there will always be someone in Slytherin who wants help with their homework who will conveniently forget that I am a traitor," Severus retorted.

Lily was having just as difficult time over with Potter and his cronies. He could hear their disparaging remarks about him. Greasy, oddball, big nosed, sneaky and a swot. Those boys had no imagination. Once Lily and Severus had put the potions right Slughorn announced that those whose potions were done could leave the class after they had provided a sample which he would test in his leisure. Severus smirked at Lily as they both arrived back at their table.

"Tick tock" he whispered. Lily just ignored him. They poured out their samples and headed in the direction of Slughorn. Lily deliberately made sure that she would pass Potter's table on her journey. Suddenly she gasped and poured a drop of her potion on Potter's head which immediately swelled up to the size of Hagrid's largest pumpkins. Potter goggled at Lily or rather attempted to do so which was difficult as he was trying balance his head.

"Professor, Lily spilt her potion on James," Sirius yelled. Immediately the whole class and Slughorn turned in Potter's direction. The whole room erupted. Slytherins and Gryffindors alike were splitting their sides in laughter. Severus could not believe that she had the audacity.

"Potter, you're lucky that for once Lily made an under par potion," Severus remarked loudly.

"Are you mad Snivellus? Can you see his head at all?" Black barked.

Severus shrugged. "Personally I see no difference. Potter's head was always abnormally large".

Once again the whole room was in uproar. Only Potter and Black weren't laughing but Severus could see that Black's lip was twitching and it was only staunch loyalty to his friend that he remained relatively stony-faced.

"Well, well, let's set you to rights boy," said Slughorn jovially patting Potter on the back.

"Ooops I am so clumsy," said Lily in a clearly fake tone. An unidentifiable noise came from Potter.

"What is it Potter?" asked Slughorn.

"She did it on purpose," replied Potter.

Slughorn looked taken aback.

"Of course she didn't and no harm done. Lily would never do a thing like that. Would you Lily?"

"But I did Professor" Lily answered and looked defiantly at Severus. However, Slughorn just burst into laughter.

"Oh Lily, you are a ticket! As if .." Slughorn laughed loudly. He clearly did not believe her. Severus caught Lily's eye and grinned. Slughorn sobered after a moment to concentrate on the matter at hand.

"Well that is one potion I don't have to test. Perfect as always Lily," he said beaming at his favourite student.

"Excuse me sir, but James needs the antidote" Lupin interupted.

"Oh indeed!" answered Slughorn as he rushed off in search of an antidote, "I know I have one here somewhere". After a five minute search he still had not found one.

"Seems like I will have to make one from scratch so Mr Black and Mr Lupin you had better escort your friend to see Madam Pomfrey".

Severus looked at him incredulously. Imagine not having an antidote on hand. In classes like Potions where accident or not so accidents could happen that was just ridiculous.

"Well off you all trot," Slughorn boomed. Severus and Lily handed up their samples.

"Told you so, Lil," Severus said as they packed up their things.

"Ah shut up, Sev."

"I'm looking forward to seeing you in Slytherin colours come Saturday."

She thought hard for a moment and then she replied "I may have promised that I will wear your Slytherin scarf but I can still wear as much of the Gryffindor colours as I want."

Severus looked at her with a mixture of amusement and admiration.

"You should have been in Slytherin!" he declared.

"Well, except for that drawback of me being a Muggleborn," she replied sardonically.

Slughorn watched as the two friends left the classroom musing on the unlikeliest of friendships.

"Oh darn," they heard him mutter as he remembered that he was supposed to be making an antidote.

The End

Thank you for reading.