Harry senses it before Dumbledore calls his attention to it.
The sound of the footsteps increase with each step, drawing closer to where he and Dumbledore sit, and Harry tenses, not knowing what to expect.
Dumbledore’s whisper of contentment barely registers with Harry as the sight of his past teacher, the man he had once hated and misunderstood, comes into view ahead of them, pacing on the platform.
Harry immediately sees that the man is not the age he had witnessed him die at, but a teenager instead.
In fact, Harry realizes with a start, they’re probably around the same age.
Snape doesn’t acknowledge them; Harry suspects he doesn’t even know they’re there, for he appears to be lost in thought as he turns his back on them, staring straight ahead, stock-still.
“Professor,” Harry says quietly, his eyes never wavering on Snape. “What is he doing?”
“Waiting, I expect,” Dumbledore answers casually, and sure enough, the rumbling sound of a train approaches ahead of them, coming to a halt with steam billowing in the air, slightly obstructing Snape from view.
Harry squints and manages to make out Snape boarding the train.
Harry’s eyes travel along the train, peering through each window into the compartments; some of them are empty, and some of them are filled with people, children and adults alike.
Only when he looks into the fifth compartment and sees the dark red hair of the teenage girl sitting in it, leaning back against the seat, does he hold in his breath.
As he watches, the door of that particular compartment slides open, revealing teenage Snape, his black hair framing his face.
Harry’s mother jumps up at the sight of him, pulling Snape into a hug; at this Snape grins so widely, color flooding to his face, that Harry thinks it’s the most alive he’s ever seen Snape look in his life.
As Lily pulls away, she sits back in her seat as Snape proceeds to sit in the seat opposite hers.
Lily is smiling, too.
This, Harry realizes with a jolt, must be Snape’s version of a happy afterlife.
The thought leaves him feeling forlorn, recalling the memories Snape had given to him to see before he died, but Harry knows that, truly, if there’s anyone that deserves happiness, it’s his past Potions professor.
At this thought, Snape suddenly turns his head, looking out the compartment window.
Their eyes lock.
Snape’s face is expressionless, and Harry, almost without realizing what he’s doing, lifts his hand up, fingers outstretched in a solemn wave.
I’m sorry. Thank you. I wish I had known before.
Snape’s dark eyes widen slightly at this, and in this moment, Harry fully expects a turn of the head or a sneer.
But to his complete surprise, those things don’t come.
Instead, Snape merely inclines his head towards him in acknowledgement, then diverts his attention back to Lily, his lips forming words Harry can’t hear.
Lily responds with a smile.
The train begins to move, picking up speed until Harry has lost sight of Snape and his mother, the compartments blurring past.
Soon enough, only steam is left behind in the train’s wake.
Harry’s hand slowly lowers to his lap.
He looks over at Dumbledore, and Dumbledore looks back at him with a cheerful smile, his blue eyes twinkling in that familiar way.
“Tell me one last thing,” Harry says. “Is this real? Or has this been happening inside my head?”
The smile grows even bigger on Dumbledore’s face, his voice booming in the mist that has now begun to envelop him, blocking Dumbledore from view, and Harry knows that he will be back in the forest any second now, and tries to ready himself for it.
After all, he knows what to do now.
“Of course it is happening inside your head, Harry, but why on earth should that mean that it is not real?”