Lilith was sitting on her bed, reading a potions book with Midnight sleeping on her pillow. She looks up from the book when she hears a knock at her door.
"Yeah?".
She hears Tom reply, "Hey sweetheart, it's me. Can I come in?".
"Sure grandpa".
As Tom enters the room and sits down next to her, Lilith closes and puts down her book on her bed. Midnight seemed to notice Tom's presence as he woke up and climbed into his lap. Tom smiles down at the small cat and gives him a scratch behind the ear.
Looking up at Lilith, he says, "You having a good morning so far, Lil?".
"Mhm. Did daddy leave already?".
"Yeah, he's got a lot to prepare before school starts tomorrow".
"I can't believe I'm going to Hogwarts".
"I know sweetheart, me and your father have been waiting for his day since you were little. That reminds me, I wanted to ask you something".
"Okay".
"I remember when you were about seven or eight that you asked Severus if you could have another pet. So I was thinking that, before you leave tomorrow, I could take you back to Diagon Alley and get you another one".
Lilith gasps and hugs Tom, "Really? Thank you grandpa. Can I get a snake?".
Tom laughs quietly, "Of course you can. Are you sure you wanna go back to Diagon Alley after last time?".
"I should be fine as long as we don't run into anyone".
"That shouldn't be a problem at all sweetheart. You want to go now?".
As she nods to Tom, the both of them stand up from the bed. Lilith takes Tom by the arm and he apparates them back to Diagon Alley. Looking around, they notice that there weren't as many people there as last time, so running into the Weasleys or Granger shouldn't occur.
Tom puts his hand on Lilith's back and leads her towards Magical Menagerie, a pet shop on the northside of Diagon Alley. Entering the store, Lilith scans her eyes around and finds where the snake enclosures are kept. She walks over and starts examining each of the snakes.
"You looking for anything in particular, Lil?".
"I'm not really sure, to be honest. I've always been fascinated by Basilisks".
"Very true". He points to a snake a couple meters away from them, "How about that one? It looks to me like a baby Basilisk".
Walking over, Lilith leans down and makes eye contact with the Basilisk.
"Hello there little one".
The snake raises its head, "A speaker. Intriguing".
"My grandfather's been teaching me Parseltounge since I was young".
"You impress me, young human".
"You impress me too. Would you like to come home with me?".
"I would love to".
Lilith reaches in and lets the snake crawl up her arm, "Do you have a name?".
"I don't believe so".
"How about I call you...Diablo?".
Tom smiles at the interaction as Lilith walks around gathering a few more supplies. He hears her mention Nagini to Diablo to which he seems to be happy to have another snake around. She was definitely in a better mood now. He walks up to the counter and pays, putting his hand on the small of Lilith's back and slowly leads her out of the store, with Diablo around her neck. Once they exit the store, Tom apparates them back to her room.
The rest of the day, before Severus got home, Tom and Lilith set up Diablo's enclosure in her room. Midnight seemed to get along with Diablo well and Tom even introduced her to Nagini. She immediately started to treat Diablo like her own offspring, which they thought was really cute. When Severus got home, he seemed surprised at the new family member, but ultimately was happy that Lilith was feeling better.