It is Heimdall who finally finds Loki, adrift through the endless black and brings him home. He hears all so he knows how the Aesir marvel when he first takes the task upon him. Most assume he wants to punish the young God personally for the grievance he caused him. Others think he's just at dead ends without the Bifrost to guard. Heimdall doesn’t bother to explain himself. He is used to being ill understood by his people.
It is an oddity of many of the immortal races and the Aesir in particular, that they remember without truly remembering at all. It isn't long (only a few short centuries truly), before Loki's actions lose their sting and are recounted at the diner table as just another example of Loki's outrageous behaviour. A humorous reminder that Odin best keep a close eye on his youngest. Heimdall never forgets.
When Heimdall delivers the lost Godling to his father, there is no punishment waiting and even the ones who once spit the ground whenever Loki's name was mentioned, are genuinely happy that Asgard will be a little less dull now.
Heimdall sees all. The pale frost that glimmers just beneath Loki's pale skin as Thor hugs him. The chill that drifts through the warm hall with every shaky exhale. The way those slim shoulders hang under a burden to heavy to carry and knows that nothing has been fixed. Loki remembers as well. It is that which has always made him truly strange amongst the Asgard. The way he holds onto every slight, every hurt and could never comprehend how easily his fellows brushed these off. It is what allows every Jotun to hate so fiercely. If Odin had understood their nature more clearly he might not have chosen to teach his Frost giant son to despise his own nature. If Heimdall had been a better guard, he might have explained this to the king before this damage had been done. Too long has he used his duty as an excuse to turn his considerable attention elsewhere.
"Did you ever wonder why I wasn't affected by the ice you encased me in?" Heimdall asks conversationally as Loki casually vanishes the incriminating powder he was just mixing in with the main mead supply. Smiling pleasantly like he wasn't just caught in the act. Many would call this a childish prank. Heimdalll knows it to be a pattern.
"Obviously I knew it wouldn't hurt you." Loki says. Insincerely. He's a gifted liar and most Asgard have learned to doubt his word on principle rather then try to divine whether he might be telling the truth. The fact that he's not even bothering to be convincing is another pattern. It is not one Heimdall likes.
"It would have killed any other Aesir." Heimdalll corrects.
"Mighty Heimdall. You are unlike any other." Loki flatters, leaning back against the vat of mead and making it shake seemingly by accident.
Heimdall can hear the pop and sizzle as Loki's poison mixes in with the alcohol, but doesn't comment. He trusts the Godling not to do anything truly malicious. For now.
"This is true." Heimdall concedes. "But I am hardly the only God with Jotun heritage."
He was expecting the attack, but still the punches are too easy to duck. The spells barely singe. Loki makes it a challenge not to beat him bloody. Heimdall is dismayed to say that he fails in this before he manages to grab the young God in a choke hold.
"Hear me Loki Odinson. Loki Laufeyson. Before the war many of our people boasted off their mixed bloodlines." The body twitches in his arms. "We should not have allowed our brethren to shame us for what deserves no shame." The body in his arms is going limp. More out of lack of oxygen then anything else Heimdall suspects, but it doesn't matter as long as he listens.
"You are the son of kings and you have nothing to be ashamed off."
Loki falls to the floor when Heimdall releases him. Tears in his blood red eyes. Heimdall leaves him there.
At the next feast Heimdall draws a lot of attention by his presence alone. He has lived on the edges of Asgard society for longer then many of his people have been alive. Ensured of the eyes and ears of the guests, it is easy to start reminiscing of his mothers.
This leads to some confusion, particularly among the younger Gods.
"What do you mean, you have nine of them?"
"How does that even work?"
Heimdall figures he's going to have to answer a lot of difficult (and frankly rude) questions on the technicalities of having nine mothers in nine different realms, but decides it is worth it, when he speaks of his mother Ulfrun from Vanaheimr and a delicate tear rolls down the cheek of Freya, goddess of Love, before she starts to share her own memories of growing up amongst the Vanir. It has been too long since such things were spoken off openly.
Loki remains silent. It doesn't matter. Heimdall knows he won't forget.