Basic intro into Harry Potter. The book stating that Harry Potter was born with a twin sister. Voldemort came in and attempted to kill them, but got vaporized instead. Harry and his sister get sent to the Dursleys by Dumbledore. Harry and Alexei Potter are left on the doorstep, only to be found when Petunia Dursley opens the door the next day to set out the milk bottles.
"What's wrong, Pet?" Vernon Dursley asked, having been woken up by her scream.
"Them!" Petunia shouted, frightened, pointing at the two babies lying on the doorstep.
The two babies jolted awake at the noise Petunia had made. A baby with unruly black hair, emerald green eyes, and a swollen lightning shaped cut on his forehead looked up at them, seemingly curious. The other baby, with thick, curly, black locks, and sea green eyes, looked up at them, then went back to sleep.
"Take them inside, Petunia," Vernon Dursley rumbled. He was feeling rather shocked that he had been dismissed by a baby.
Picking up the two babies, Petunia stepped into the house, nudged the milk bottles out the door, and then silently shut it. It wouldn't do to wake up the neighbors, after all.
"They're Lily's," Petunia spat out. "They're freaks like her."
Holding the note she'd found attached to the male baby's blanket out to her husband she watched as he processed the information that was on it. As Vernon read the note his face was turning an unattractive shade of puce.
"We'll take'em to an orphanage," Vernon growled out.
"We can't!" Petunia cried out, "Dumbledore says that as long as they're here we'll be protected, because of some type of blood wards."
After a long discussion Petunia and Vernon decided that, no, the babies wouldn't be thrown out. Instead, they would be put into the cupboard under the stairs. Thus, Harry, and Alexei Potter began their new lives at the Dursley's.