Lines of Poi­son Lon­gi­tude set the stage for a piv­otal jour­ney on the open sea, where a group of sailors faces mount­ing chal­lenges under increas­ing­ly per­ilous cir­cum­stances. Sol, in her efforts to gain her grand­fa­ther Griff’s approval, con­tin­u­ous­ly pro­vides food and tries to keep the mood light, but a sense of dread looms over the crew. Griff, a man with dreams of grand adven­tures in the past, remains a fig­ure of com­plex­i­ty, bring­ing to the table his fan­tasies of liv­ing the life of an astro­naut and claim­ing a place among the stars. As Griff takes con­trol of the ship, his lack of prac­ti­cal sail­ing knowl­edge becomes imme­di­ate­ly appar­ent. Despite his lofty ambi­tions, he stum­bles with basic nau­ti­cal com­mands, unable to prop­er­ly nav­i­gate, lead­ing to the boat veer­ing off course mul­ti­ple times, cre­at­ing chaos and con­fu­sion among the crew. The once calm and idyl­lic atmos­phere on the boat begins to unrav­el, and Sol’s attempts to help her grand­fa­ther are met with increas­ing frus­tra­tion.

As the day con­tin­ues and the weath­er begins to wors­en, Griff becomes more deter­mined to assert his com­pe­tence, attempt­ing to show off his knowl­edge of weath­er fore­cast­ing. His home-made almanac, filled with pre­dic­tions about future weath­er con­di­tions, demon­strates his con­fi­dence, but the rapid­ly dete­ri­o­rat­ing weath­er con­di­tions make his efforts increas­ing­ly futile. The winds pick up, and the seas grow rougher, caus­ing Griff to spi­ral into pan­ic, unable to man­age the cri­sis he’s cre­at­ed. His stress leads to a dan­ger­ous mis­take when he opens the intake valve, near­ly flood­ing the boat and threat­en­ing to cap­size them all. The ten­sion on board reach­es a break­ing point, with the crew fear­ing for their safe­ty, but Sol’s quick think­ing saves the day. She swift­ly shuts off the intake, pre­vent­ing dis­as­ter and bring­ing tem­po­rary relief to the crew. Though the imme­di­ate dan­ger is avert­ed, the group remains shak­en and uncer­tain about what comes next, their nerves frayed by the ordeal.

The night is filled with anx­i­ety as the crew bat­tles rough seas, unable to find any rest. The weight of the storm, com­bined with Griff’s dete­ri­o­rat­ing phys­i­cal con­di­tion, exac­er­bates the sense of unease among the group. Griff, already frag­ile, suc­cumbs to the stress, his health fail­ing him as he los­es con­scious­ness. The pro­tag­o­nist looks on help­less­ly as Grif­f’s state wors­ens, and the crew strug­gles to stay afloat in the tumul­tuous waters. With no end to the storm in sight, their jour­ney grows dark­er, and hope is a fleet­ing feel­ing. How­ev­er, as dawn breaks, the sight of land pro­vides a brief moment of solace. They spot an island on the hori­zon, offer­ing the promise of shel­ter from the storm and a poten­tial safe haven for the weary crew. But the arrival of this island brings with it a new threat: a ship anchored near­by. The appear­ance of this unfa­mil­iar ves­sel casts a shad­ow over their brief relief, as the ship’s pres­ence adds an omi­nous tone to the already dire sit­u­a­tion.

The mys­te­ri­ous ship rais­es the stakes for the crew, trig­ger­ing a sense of fore­bod­ing among them. Its weath­ered and decay­ing exte­ri­or sug­gests it has been aban­doned or left to dete­ri­o­rate, adding to the unease felt by the crew. As the crew sur­veys the ship from a dis­tance, their instincts tell them that dan­ger lies ahead. Among the fig­ures aboard the ship is Tom Skint, a man the crew rec­og­nizes from pre­vi­ous encoun­ters, whose appear­ance height­ens the sense of impend­ing con­flict. Skint’s pres­ence sug­gests that the crew is not yet free from their past trou­bles, and his con­nec­tion to the mys­te­ri­ous ship only fuels the ten­sion. The chap­ter clos­es on a note of antic­i­pa­tion, with the crew unsure of the inten­tions of those aboard the ship, but cer­tain that the com­ing con­fronta­tion will be inevitable. The once promis­ing idea of find­ing sanc­tu­ary now seems dis­tant, replaced by the loom­ing uncer­tain­ty of what this new devel­op­ment means for their jour­ney.