Severus knew he had little choice in what was about to happen. If he was honest with himself then he knew that Voldemort giving him a 'choice' was just sealing the fact that he had no choices. Voldemort and Potter having spawn together changed everything.
"Fuck." Severus muttered to himself as the potion he finished brewing proved that Elaine was indeed the daughter of Tomos Riddle-Slytherin.
"So it is true?" Voldemort said from the doorway of the potion's room, startling Severus.
"Yes, Elaine is your daughter. Without Potter's blood, I can't confirm him as her bearer but it is likely also true. The Potter genes are strong in all five children so it doesn't leave much doubt." Severus said in a tired voice. Voldemort studied Severus, seeing the weight of being a double, or even triple, agent weighing heavily on his shoulders almost in a physical manifestation at this point.
"Severus, I respect you more than most. If you have betrayed me, I will not retaliate. Even if you wish to permanently turn your back on us, I will let you leave and return to Dumbledore. Your playing both sides ends now." Voldemort said in a calm even voice, watching Severus slightly hunch in on himself. Walking closer to the dour man, Voldemort lightly placed a hand on Severus' shoulder.
"But I also do believe it is time for you to face the facts. If those children are both mine and Potter's then the whole war is about to shift on its axis. I see in your eyes the remaining promise you made to young Lillian to protect her son. Those are her grandchildren and she probably would have wanted them safe as well. Ask yourself the question, is the young Potter and his children safe remaining on the Light side with Albus? Make your choice Severus, we leave to raid the Black family townhouse in five minutes. If you do not join us, I will know you have returned to Dumbledore and you will no longer be welcome among us." Voldemort squeezed Severus' shoulder once before letting go and turning around, leaving Severus alone with his thoughts and Lily's voice in his head accusing him of not saving her baby.
*PLTS*
The Order of Phoenix was gathered in Grimmauld Place's dining room when the wards around the townhouse began to shiver. Unfortunately for those within the townhouse, the only one connected to those wards rightfully by blood was unconscious upstairs.
So when the wards fell with a sharp crack and the house began to shake with the force of spells hitting its foundations, the order was overwhelmingly underprepared for an assault on their safehouse. The cowards of the group such as Mundungus, apparated away immediately, leaving the others to face the assault alone.
Albus was feeling all of his 114 years of age. The only way someone found Grimmauld through the fidelius is that they were betrayed, yet again. When he found the traitor he would bury them alive this time. He did not have time for all of these pointless detours from his grand plan. He needed to handle the traitor, he needed to get rid of the Potter children, and possibly obliviate Potter while he was at it. He needed Harry to be focused on defeating Voldemort and nothing else.
But first, to handle these intruders.
*PLTS*
"Find the children and portkey them back to the manor immediately Severus. You know this house better than the others. Try to avoid dueling unless you have no other choice. I want them out of here so I can just light this dirty hovel on fire." Voldemort growled through clenched teeth. He was holding the wards up that protected his overzealous death eaters from making the foundation completely collapse in on top of them.
"Yes, my Lord." Severus nodded, putting his mask on before disappearing into the chaos of the townhouse.
"Oh, Albus! I know you are in there! Come out and face me!" Voldemort used a sonorous to call out to Dumbledore and taunt him. Giving his followers a better chance of avoiding a run-in with the powerful headmaster while they wreaked havoc inside.
"Tom, I do not know who you manipulated into betraying our location, but you must know attacking the Order so blatantly is poor planning for even you," Dumbledore said in a disappointed tone as he walked out of the front door of Grimmauld Place.
"Well, your precious Order doesn't seem to be doing you any favors, old man. Those screams certainly aren't from my people, so I would naturally assume they are yours failing to fight back." Voldemort taunted more with a nasty grin on his snake-like face. Dumbledore fired off a stunner clearly over trying to talk with Voldemort, causing the evil man to grin.
*PLTS*
Fighting inside of the Black family townhouse was the stupidest thing they had ever done, Severus thought as he dodged spellfire and falling cursed artifacts coming from Gods know where.
Severus made sure to stun any Order member he came across but otherwise moved swiftly up the stairs searching for Potter and his spawn. He came across the eldest first and had to admit to himself that the boy was doing well holding his own against Tonks and Kingsley, two well-trained Aurors. The boy moved with the practiced grace of a professional dueller, although his method of fighting did remind him a lot of the Dark Lord. Shooting a silent stunner into Tonks back, Severus watched as the blonde boy cut Kingsley down ruthlessly in a way that not even Potter could do.
Before he could move Armand had his wand trained on Severus before seeing it was a death eater. "Did Father send you?" Armand asked in a shaky voice. Maybe he wasn't as battle-hardened as he looked.
"Yes, Voldemort has sent me to retrieve you, your siblings, and Potter. I have a port key to take us out of here while he distracts Dumbledore." Severus said quickly, really not wanting to stay in the house longer than necessary.
"My siblings are upstairs but Dad and Aunt Hermione are locked in a room on the top floor. I directed Elaine to take the others up to where Dad is but I do not know if they have been successful in getting in." Armand reported, leading the way up the stairs.
"If they haven't gotten in then I can get us in," Severus muttered, protecting their back from getting hit by stray curses. Most of the fighting was on the bottom floors, it seemed Severus was the only death eater to make it this far into the house, but he wouldn't hold his breath that more order members weren't hiding further in.
They reached the top floor in quick time, the other Potter spawn were firing what seemed to be any spell, curse, or hex they could think of at the door of what used to be Sirius' room.
"I don't think jelly legs jinx is going to do you any good Jai." Hermione's voice said through the door, sounding as if she had been running a marathon.
"Miss Granger, stand back from the door," Severus called out as Armand shuffled his sibling back away from the door as well, ordering Elaine to keep a lookout for any Order members coming up the stairs.
"Professor Snape?" Hermione asked unsurely.
"Yes now step back quickly, we don't have time for you to question me." Severus snapped. When he heard her move away from the door he cast a complex unlocking charm that he knew would counter one of Dumbledore's favorite spells. The door started to crack and split before exploding into a bunch of splinters causing all the children to let out a startled scream.
"Some warning probably would have been good sir." Hermione grumpily muttered from where she had ducked down behind a nightstand.
"No one died. Now, what is wrong with Potter?" Severus asked seeing the boy unconscious on the bed still, his fainting fit from earlier shouldn't have kept him asleep this long, especially through the noise of the fighting in the house.
"I don't think anything sir, Mrs. Weasley said they had just cast a sleeping spell on him so he could get some rest," Hermione said while wringing her hands nervously. Severus inspected the boy quickly, just checking to make sure nothing would interfere with their portkey.
"It should be fine, I need all of you to gather around and grab the rope, I believe you will be joining us, Miss Granger?"
"You can't separate me from Harry and I don't trust you."
"Then grab the rope, I'll grab Potter and activate the portkey," Severus ordered. Picking up the surprisingly light boy off the bed as Hermione and Armand got everyone with a hand on the rope.
"Slytherin's Sanctuary." Severus intoned, activating the portkey and alerting the Dark Lord to their departure so he could sound the retreat and activate the spells previously shot at the foundation of the house to cause it to collapse in on itself. Severus only regretted not being able to watch Dumbledore's face as their safehouse fell in on itself.
Maybe his Lord would allow them all to see the memory later.