Okay, here's what happens given the location:
Average day, working at inn. guest checks in, room is given.
Next day, odd cracks appear in ground, investigation amongst townspeople, guest shows up in evening for second night.
Third day, while trimming grass near inn, small, translucent tendrils grabs nearby animal, who then mutates slightly and attacks. you kill it with grass scythe. run inside, explain situation, guest pays vague attention before leaving for the day. that night, a cracking noise is heard, sky has a faint, glowing cracked pattern in it (too faint to see during daytime.)
Fourth day: guest seen investigating around town, scattered reports of attacks in the forest, assumed to be highwaymen. tendril crazed person says something in an indecipherable language and passes out. recovers in hospital with horrible memories.
Fifth day: other people report odd sightings in forest, describing the same tendrils as before, guest drops odd object, looks futuristic. small siege of monsters at village gate cause emergency town meeting. guest sows up to meting as well.
Sixth day: cracks grow brighter and more numerous, guest seen speaking to himself in the middle of the night. monsters from deeper in the forest emerge in city.
Seventh day: after guest leaves room, you decide to take housekeeping duty in order to investigate the suspicious guest, suspecting he might be the cause. Empty sword hilt, bizarre looking knife, some futuristic looking gadgets found, and a map of the village is found, with a date written on it and an "x" over where the ground and sky cracks seem to converge. record of attacks found, as well as record of similar attacks from places you've never heard of. You put everything back where it was and go on to clean other rooms. that night, you return the gadget the guest dropped, who thanks you profusely for it, and leaves for his room.
Eighth day: Guest seen around the marked location on map with the returned object. You ask him what it is, but he dances around th question. other villagers are growing more suspicious of him as well. attacks from mountain creatures occur. at night, guest is seen with empty hilt near the same spot, while the cracks worsen. a strange creature appears of the same material as the tendrils. it attacks the guest, who attempts to use the empty hilt as a weapon. the creature inexplicably becomes sliced up and de-materializes. smaller enemy forms as guest walks away, jumps him, knocking sword hilt away. boss battle with otherworldly entity.
Ninth day: guest takes you aside, and explains partly what happened. it was a creature from another universe attempting to invade. bag of maps found near battle site. they all have vastly different buildings on them, but the terrain is the same as the town. more monster attacks, but the town's newly organized task force handles it well.
Tenth day: tendrils envelop a house, guest seen with knife slashing at the tendrils, you join in helping, and he hands you the hilt. You enter the house, help him rescue the inhabitants and have a boss battle with a large tentacle. you escape with occupants, house is crushed and lies under field of writhing pink. guest checks out of inn at evening.
Eleventh, and twelfth day are worsening cracks, investigation in town archives, and ever stronger monsters. records show nothing of any sort of event, but a somewhat rambling book describes similar circumstances. no sign of the guest.
Thirteenth night: sky breaks, gigantic pillar slams into ground, half of the town is decimated. winged warrior shows up with empty hilt, along with the guest and several other fighters. you still have the knife, which as mechanical parts in the blade running at full speed. you aid the mysterious warriors in battle. during battle with the pillar, you learn that it's from another type of universe, in which time works differently. it attacked the planet in the same spot, just at different points in history, which is where the other warriors are from. straight on boss first form, puzzle boss second, third is curbstomp battle (against you.) guest uses beam weapon as last ditch effort, it opens a weakness, but the gun overloads and explodes, killing guest. final form is a low hp match between the remaining party and pillar. after defeat, the pillar disappears, and is erased from the time line, reversing the damage. guest (never named.) is buried, and other warriors offer for you to join them. sequels take place in same town, just at different timeframes. (metropolis at one setting, just forest land in one, etc.)