Disclaimer: I'm pretty sure The Odyssey is public domain, but regardless, I don't own it and neither do I own OUaT.
So the short of it to get you up to speed: Emma has grown up a princess in the Enchanted Forest, James is still alive but the younger twin, and guns are a thing that exist in Fairytale Land but they don't really matter but they kind of do.
Emma had realized only a few days after setting sail that her parents - in spite of and perhaps because of her desire for a year of irresponsible adventure and thrill at sea - had managed to put her on the safest, most out-of-the-way ship their navy had. That, or they'd put her Uncle James - who Emma had chosen as her guardian for the next year, and as a noble of high birth had to be in charge of something - in command of the most inconsequential major ship they had.
Really, by month eight, she was convinced it was both. Because her uncle almost certainly had to be the most useless sailor she would ever come across. He drank himself witless half the day, parked them in any port city they were allied with every night for more drink and women to bed and gambling halls to throw his brother's money away in, and every early afternoon awoke to start all over again. Which honestly was why Emma had chosen his ship to sail on in the first place. She'd figured, "What are my chances of getting lectured by Uncle James? Zero. This year is gonna be a months-long party!"
But no, because it quickly turned out that they couldn't both be useless, irresponsible womanizers. That shit got them fifty leagues into enemy waters with half the crew threatening mutiny and the other half blacked out in their bunks stinking of whiskey. At least one of them had to be sober and in some semblance of in-charge, and it was never going to be Uncle James. And so it was that Emma's first year of adulthood was spent actually learning how to be an adult; how to tend the netting and supervise the ship's crew and measure the ship's course in the stars and from the almanac. How to drink sensibly and how not to talk about people behind their backs - because on a boat rumor always always always ended up in the most inconvenient ears - and how to be the leader her parents wanted her to someday become.
Which was some bullshit, because she had, like, years to worry about learning that.
"Uh, y-your highness?" a voice called from starboard. She turned to the dwarf, Bashful, as he started up the stairs to where she stood next to the bridge having a conversation with the helmsman. The dwarf was looking everywhere but at her face and holding a roll of parchment between his two white-knuckled fists.
"Yep?"
"A, um, a message came-" he began before breaking off to take a massive intake of breath. He steadied his stare at a space two inches to the right of her and started again. "A message from his majesty the k-king arrived by hawk a few - *gasp* - a few minutes ago. And I - I tried taking it t-to his highness Prince James, b-but he's asleep-"
Blacked out with a bottle of rum in one hand and woman's tit in the other more likely, but Emma let him continue without interruption. She'd found that people like Bashful shouldn't ever be interrupted, as it only slowed them down, made them think even harder about the mistakes they thought they were making and how the people they were talking to were reacting to them. Interrupting panicky people like Bashful made them panic even further, and he was clearly upset enough.
"-so I opened it myself to see if- if it was urgent and Snow - *gasp* - her majesty - the queen h-h-h-h-h-h-he-ha-has-"
"Yes?" Emma prodded, unable to help herself.
"-sh-she's ill, Emma!" he said, and promptly burst into tears. "Gravely ill!" He fell into her arms and she hugged him tightly, reaching to pull the parchment from his hands behind her back.
It was indeed in her father's hand, though rushed and splotched with hastily spilled ink. Reading for herself, her mildly concerned frown quickly deepened. A wasting sleep, the message said, which no magic or clinical cure had succeeded in waking her mother from.
She thought only a moment before telling Bashful, "Wake Prince James. Loudly. Tell him what's happened and that we are changing course back to the Enchanted Forest." She disentangled herself from him and turned to Uncle James' second-in-command at the helm, telling him to likewise set course west. It seemed that her father's wish that she become a better leader during her time at sea had come true, as both followed her will without a word. Bashful scurried belowdecks and the sailor spun the wheel counter-clockwise.
Far as they had been - almost half a world away - when they'd been given cause to turn back for the Enchanted Forest, they made a lot of headway in the following days. Emma ran the seamen ragged, pacing the deck at all hours of the day, measuring the stars obsessively by night and all the while thinking, hypothesizing a cure for a sickness she knew only vaguely of. Even James had been spurred into semi-usefulness by the news, unwilling as he was to get any closer to ascending the throne - and therefore taking on any more responsibility than he'd ever want to deal with - than he already was.
It was late in the morning and three days since they had received the message about Queen Snow. Emma was taking a quick lunch in her quarters. She pushed baked fish into her mouth with one hand and flipped through an almanac with the other, considering the coming days' weather and adjusting the time frame to allow for hiccups that may be met.
Emma had turned back to the the section of the moon's cycles and had picked up a quill to take notes when a bell began to clang overhead. She'd only heard it three times before during her time at sea, all when men had fallen into the water and the ship needed to be stopped to pull them back aboard. Nevertheless, she left the uninked quill in the almanac to mark her place and started up the stairs to check that things were alright.
She ascended into chaos, into ineffectual sailors bobbing and flailing like cats dropped into shallow but wide-gaped pools of water. Directly in their path a small cluster of black-painted ships cut through the waves toward them, black flags with red skulls and crossbones flying at the tip of their masts.
"Pirates!" a white-haired sailor provided to Emma before diving overboard.
Across the deck, Uncle James was climbing up from his own set of stairs. Swaying on his feet and glaring blearily at the oncoming ships, he held his hungover head in his hands and yelled, "Turn around!"
"Your highness," the man at the helm said, "With all due respect, the time it'll take to turn around will have them on us in minutes. We should change course directly south!"
"The skies are black with clouds that way!" Emma argued. "We'll be sailing straight into a storm!"
"Aye, your highness, that I know!" said the sailor, "But that red is that of Captain Hook, and he doesn't take hostages, your highness. He's the one who sliced off the late King Alistair's head five years ago in his own capital's port! Better the risk of drowning than the certainty of his sword!"
"...Fine," she said after a pause. She turned around her to the distressed seamen and raised her voice to be heard over the rabble. "But calm down, all of you! Get your swords out from wherever you've stashed them all these months! And buckets for the rain and whatever else is needed. Act like the sailors you've been trained to be, for gods' sake!"
"Aye!" said one sailor in the crowd, and the agreement was soon lifted up by another and a few others after that, but it failed to gain any real traction before the sailors pushed each other belowdecks or to adjust the sails or man the cannons. They hurried, but they fumbled, hands slipping and voices whispering worry to each other.
"Not my first evasion, your highness." said the man at the helm to Emma. "We'll get through this with limbs to spare, trust you me."
They did not.
They outran Hook's ships for two hours before a fork of lightning blew their main-mast in half and left them stranded and still in the water. The shorter mizzen-mast and the entire base on which the helm stood was blasted apart by cannon-fire from the frontmost pirate ship, taking the wheel and anyone standing around it into ruin as the naval ship careened on its side. The railing met the rising water for an inexcusable number of seconds before righting itself, but not before taking half the crew under the water's surface and tipping the other way. Emma, clinging almost horizontally to the trunk of wood that used to be the main-mast, with four other sailors clustered close around her, could only watch as the foremost pirate ship reined close enough for a score of pirates to jump aboard.
"Your highness!" a voice close to her ear shout-whispered as soon as the ship righted itself and they fell back to the floor. It was Eustice, a short fellow with brown hair and bronze features who mostly kept to himself. He pulled her by the arm to the opposite side of the ship and back to where the one lifeboat still hung on its ropes. He climbed aboard and extended a hand to lift her in with him, but she hesitated.
"I can't leave all of them to die, Eustice!" she said.
"All due respect, your highness, they're gonna die anyway!" Eustice said, tugging at her sleeve. "Hell, we might still die! Now come on!"
She grasped his hand and he pulled her aboard. She was halfway in when a gunshot rocked through the air and pierced straight through her shoulder and into Eustice's right knee. In one ragged motion, the sailor unsheathed his sword and cut the lifeboat from its restraints. As they fell, another bullet whistled past Emma's ear, and where it landed she knew not, as her eyes were shut tight against the pain arcing through the entire left side of her torso.
Something was pushed into her right hand and she suffered her eyes open. Tightening her fist around the oar, she looked up into Eustice's pale face. "Row, your highness." he gasped, red-stained hands fixed around his own oar and a dark splotch spreading out from his stomach. "Hold it under the water and push. You see that island behind me?"
"Whaaa..." she was already starting to drift into exhaustion.
He slapped her lightly on her cheeks. "See that island behind me? With the black-sanded shore?" She leaned haggardly to peer around him and nodded. "Aim for it."
"Should we go after the two in the lifeboat, Captain?" Smee asked Hook and pointed to the south where two silhouettes were escaping. He followed the pirate's finger to the lifeboat, and further to an island in the far distance. Even from far away you could see the black sand of its shores, the violet waters at its hips. And upon recognizing it Hook grinned and laughed.
"No, Smee, no need." he smiled. "They're as good as dead. If the maiden doesn't take care of them the mother will, I wager."
"And the crone, Captain?"
"...what?" Captain Hook's smile slipped in confusion. He'd said nothing about a crone.
"A crone, sir. Maiden, mother, crone. There's always the three of them, sir, in stories-"
"No, Smee," Hook waved him away. "It was only - it was something of a joke, see, because the two are witches and - but no matter, no, Smee, this isn't a story."
Oh, but it was, though he, of course, being inside of it, didn't know it for what it was. And indeed there had been a crone, though not for quite some time. But her story is for another day.
Because right now, Emma was failing to man two oars at once while avoiding Eustice's dead stare. The man had slumped onto his back a quarter of an hour into their escape, half an apology voiced before he'd lost his last breath and passed. The splotch had spread up to his chest and down his pants and into the rain pooling at their feet.
Mere minutes after her fingers quit on her completely, numb and shaking and unable to grip the oar. Blackness pooled in at the edges of her vision as she hunched over Eustice's body, trying to breathe through the pain and cry without shaking her bullet-ridden shoulder too badly. She clutched at it with her right hand, trying in vain to hold the blood in, cursing herself and her hesitation and the entire institution that was seafaring. Rain poured all around, the sea churned, her head swam and the wind bore her away. At length, her eyes fluttered once, twice, before falling shut.
She could feel the sky breaking open and the sun coming out, drying the cold from her face and burning the underside of her eyelids red. She felt hands lifting her feet and dragging her through the sand, heard waves crashing against the shore and stumbling footsteps close in front of her and a labored breathing. Cracking open her eyes, she looked up into the face of an angel with golden features and black, unbound hair; into panting red lips and worried eyes which watched the open ocean in front of them and jerked occasionally back to the path.
'Wow' Emma wanted to say, tried to say to the woman, but her voice didn't work. And almost as soon as she'd come to she was gone again, her lips rounded in unvoiced awe.