The bit in which Frodo eats, shoots and leaves.
Now that the prologue was over, Bilbo considered taking a sneaky look at his special checklist without letting the audience see it - then he reasoned that they were already leaning on the fourth wall so much they practically needed a safety rail. Anyway, the camera was probably spending time focusing on his mail on a stand and Sting - which was conveniently left out of the sheath, for some reason - and various other questy things lying about the hobbit hole.
He threw caution to the wind. "Frodo?"
"Yes, Bilbo?" his 'nephew'/adopted son/many-times-more-than-it was-really-healthy-to-be cousin answered. He was already pulling out his own copy of the list, with a resigned sigh.
"Have we loudly established our familial connection for the audience in full, by all and sundry, even though we and everyone around us should already know this by now?"
They both made ticks on their respective bits of paper.
"Have we emphasised just how much I loathe and detest my close relatives, the Sackville-Bagginses, and how the feeling is entirely mutual, with the implication that the reasons behind the feud between our houses will be unveiled throughout the coming films?"
"Yes." Tick, tick.
"Have we talked about just how exciting, and generally unlike anything the Shire has experienced before, my hundred and eleventh birthday party is going to be? And that it's taking place tonight?"
Frodo acknowledged that indeed, they had more or less covered that. Repeatedly.
"Good, good." Bilbo came to the last, as yet unticked item on the list. "And Gandalf's scheduled to be arriving today, with the fireworks. Since you've fulfilled your cameo for this section of the film, why don't you go and eagerly wait for him, while I forget that he was coming at all and thus be totally surprised when he does show up?"
Frodo gave his 'uncle'/adopted father figure/related-to-the-power-of-squick cousin a worried look. This whole list thing was just the latest example of how strange Bilbo had been acting recently. Not just because of the dark influence of the Ring, of course – which Frodo couldn't actually acknowledge, since chronologically he wasn't supposed to know about that yet, thus only adding to his own particular stockpile of neuroses. But there were also the deeper connotations of this new trilogy that Bilbo was about to embark upon. The incipient explosion of the fandom for good or ill was one, but there was the more immediate fact that, because of the plot-structuring and choices for story arcs which the directors (ALL HAIL) had chosen, Bilbo was essentially now existing in two different eras and a not-really-parallel universe, all at the same time.
It had led to some pretty odd comments over the past few, technically non-existent, months.
"Are you sure?" he asked, even as he got up. "You don't want me to stick around for the flashback, just in case you keel over or anything?"
"No, no. You need to be on time for flinging yourself ecstatically into Gandalf's tender, warm embrace-"
The older hobbit's choice of words made Frodo give him another look, which wasn't so much worried this time as just a straight out look. The multitude of years he'd been prey to a rabid public meant that very little could faze him any longer, but the fact still remained that while he liked Gandalf as a friend, it oh so definitely stopped right there.
"-and we're already running late. I'll get you up to speed – sort of - later on. Go, run, be free. Have fun not being completely traumatized for a change."
"…Thanks for that. I think."
Bilbo followed Frodo out into the front garden. Despite his previous advice, Frodo looked entirely too smug. This was worrying. "What are you looking so happy about?"
Frodo grinned, which he didn't get to do too often. It was an odd but nice, experience, even if it did make his face muscles creak slightly. "I guess I'm just gratified that it's your turn to suffer, for once."
"Technically, the plot of the films has already happened, and I have sought therapy, for my sins," Bilbo replied, kicking the gate open with perhaps a tad more force than was required. "Besides, I have an inkling that some other version of myself has had it much worse."
"Well, yeah, but you have to relive it all again and experience it at the same time," Frodo countered, sauntering out onto the road. "Plus, think of the shippers. At least I mostly got slashed with a member of my own species. Or at least another biped. Your 'incident with the dragon', on the other hand-"
"Yeah, Frodo, if the audience has seen the extended cut of Fellowship, they'll remember that I don't realise you went out, even though I'm clearly bidding you farewell now. Thus, please excuse me if I forget your existence for a little while I attempt to purge that last image from my brain, thanks awfully."
"Hypocrite," Frodo said, but he set off down the hill and out of the film until he was needed on screen again, with a spring in his step and so on and so forth.
"Yeesh." Bilbo rubbed his forehead. Still, it wasn't as if his 'nephew'/adopted son/…(let's face it, all upper class hobbits are rather inbred) had no cause for such glee. Frodo's stint as a main character hadn't exactly been fun, understatement of the Third Age there… and then there'd been the meta trials and tribulations his 'fans' had inflicted upon him.
Which were many, and hideous.
The end result was that, far from being the rather wimpy kid of his own trilogy, Frodo was now a hobbit who practically personified schadenfreude. Even at the expense of his nearest and dearest, though this time he did have the excuse of being fully aware Bilbo obviously survived, with everything intact.
Sort of intact.
Bilbo sighed, went back into his study and prepared himself for the flashback procedure. This sort of thing, he reflected, was so much more fun when he wasn't the one powering it.
As the flashback hit the brainpan, he barely had time to consider that just maybe he should have done this while sitting down. Then his mind was seized, dissected, disassembled and dragged through crackling and fiery portals, back to a time when he was younger, more innocent and played by a different actor.
As mental violations went, he'd had worse, so that was all right.