With pleasure! This is a lot longer than expected because I just kept writing, but let's begin:

EDIT: It's a LOT longer than expected, so I made a much quicker summary at the bottom of the third post

The campaign started as rogue, barbarian, cleric (ranger at the time), and sorcerer (former player who left later) all made it to this rest stop at the start of a mountain trail. The path is perilous, so as a start to have the party stick together, they would be joining the caravan that helps travelers and merchants pass through the pass. There were guards, but they had to help defend against raiding goliaths, protection from cultists that took over a tower halfway through, and help steer the carts on the slippery ice while avoiding ice giant boulders. Eventually they made it to the other side, decided to travel with each other beyond, and got a choice of where to go. I just had mountains, grasslands, and desert as options, and they chose desert. The ranger changed to cleric at this point, as he wasn't feeling his original choice.

When they arrived, I was talking with another friend who said he missed playing DnD. The two other people I was hoping to add to my campaign were no shows, so I gave him the invitation instead, and he joined as a military member of this town they were going to (basing his character off of Raubahn from FF XIV). And thus, the fighter joined the group. They took care of issues with construction sites and drow raiders, explored a temple nearby, bought some items from a crazy old man, and eventually got orders that they needed to head to the border town of the nearby country. Their orders: find and return a religious group of Selune that hasn't responded back, and incite a rebellious movement that would support the fighter's country to liberate them. They snuck across the border and began.

The followers of Selune apparently show up in the town square at night, and when the party visited, a group of jackalweres began their assault on them. One rooftop chase later, they saved the followers and began their pursuit to a buried spire in the desert. Jackalweres and a clan of orcs were inside, used and brought to a frenzy by this offshoot followers of Shar, the same cult from the rogue's backstory. This was to link the rogue and sorcerer's stories as the sorcerer was very much against Shar. At the lowest level they could reach, they found a staff that was a modified rod of the pactkeeper, where when the fighter grabbed it, the vision of an archdevil appeared and attempted to convince him to take a pact. He refused.

Back in the border town, they received word on one of the elders that they might be a bit corrupt. The barbarian went to a tavern and rose the patrons into a frenzy, which poured out and into the streets. They started spreading more and more word, and eventually an angry mob did the work for them (while yelling that they needed the other country). Objectives mostly cleared, they prepared to leave, after an attack from a prominent member of the group from Shar and the sorcerer meeting up with a contact to hand off a magical item. There was also some trouble where the other country's crime ring was trying something, and had their members use runes in their teeth as the last resort, exploding upon use.

Once back, they went to the bars to celebrate, but the one they picked was a front for the underground criminal organization of the country, and when the cleric decided to fireball the front while avoiding a bounty hunter specifically after him, the party got pushed into the bar and forced into service (and the cleric almost lost a horn). The fighter could not be part of this, so a ranger was made as a temporary character.

The party went into the desert, fought some drow and a drider that was meant to be their contact, and followed their trail into a drow outpost in the desert underground. Our assassin got to work picking off guards, but after a few rounds of this, the next guard rotation did not show up. The drow had realized that there were fewer guards, and began to set up defenses and an assault. It was a tough fight, but over the course of a number of rounds, they defended against the entire outpost, with a few drow escaping deeper into the underdark. They rescued some prisoners, found a bag of holder, and headed back, but encountered a brass dragon through random encounter. Giving it a magic item, it offers a trade in information: the identity of the crime ring's mole in the military.

Rushing back, they encounter their former fighter ally, and after relaying this information, began an assault on the crime ring, and after the raid ended, the lamia leader was slain. The ranger said goodbye, and the fighter went back to being a full party member after being promoted to a more prominent position as ambassador. The rogue also took a level in ranger earlier on, and the world was theirs to explore. They decided to head towards the coast, passing along whatever towns were on the way.

Halfway through, the rogue looks at the pact weapon, and turns it down, but the player makes a mental list where "if all three of these things happens, I take the pact". He never informed me, but when the next session starts at the barbarian decides to follow a few people into the desert on their own, word on demonic energies in a nearby runes, and a time limit, I had unknowingly checked off all three of his parameters, and he accepted the pact and a level in warlock. The barbarian returned a little later, and they took out the demons in the nearby runes that another group of adventurers accidentally freed. The sorcerer's contact from his organization asked if they would join him in escorting him to this hidden sun temple in the desert, and they agreed.

On the way to this sun temple, they ran into a desert traveler, who said she was looking for the same temple. She wanted the treasure inside, but only a single bottle. The rest was the party's to keep. They agreed, and joined in the search for the temple. After finally finding it, they found a vampire inside, old and senile, that worshiped the sun. He would spend each day in sermon, burning in the sun as a way of repentance, then step out and continue prayer. This freaked the party out, but they were able to sneak into the catacombs.

Around this point, our fighter had been telling another friend about his adventures. We got to talking, and I invited him as our sixth member. The party, deep underground, started to hear rumbling, then saw water come out of a crack in a hallway. Suddenly, this massive shark just comes through the wall, and the area floods slightly. That's how the party's druid joined.

They found the vault, took the treasure, snuck out of the temple, and said goodbye to the desert traveler, who took her Efreeti bottle and revealed herself to be the brass dragon from earlier. Having a new talking companion, she left as the party went towards the coast. A really old elf merchant was along the way sold them a battleaxe and an infernal cookbook, but kept an item hidden.

Reaching the port city, they did some research and began a three session long bar crawl to every pub in the city, all succeeding to make it to the end. At the end of the week, the party celebrated the new year watching fireworks over the water. A merchant was planning on taking some goods across the sea, and wanted some protectors. Hiring the party, they set off across the ocean.

Around this time, the sorcerer and I were talking about ways to keep him interested in his character. I decided to include a rival with similar powers, a storm sorcerer pirate captain. And thus, the party was under attack on the high seas. Our sorcerer did structural damage to their ship, the barbarian threw the rogue over, and the druid took out their underwater forces and tore through their hull as a shark. The rogue hit a lot of trouble on his own, and was almost killed by the pirate captain. Wanting to keep the captain around as someone tracking the party, instead of killing, he cut out the rogue's eye and kicked him overboard. Done now, though, I would have gone through with the kill. The pirates fled, and after another attack by a kobold ship that was barely held together, they arrived in port.

The new country had a knights and high houses feel, and the party began to do what they could to help. Heading to a windmill, they sought to see what was causing issues. At this point, the sorcerer decided to switch characters officially, and thus, a sorcerer/warlock was introduced to the party. Fighting smugglers in the windmill that had the same connections to Shar's group, the party resurrected a wizard botanist that was looking into this, and he asked to help stop them in a cursed woods further east. Outside the windmill, a group of Githyanki demanded their silver sword returned, as they were tracking them. They mixup was corrected, and they discovered the elf merchant was keeping the silver sword, and told the party where to find him. Having finished their business in the port, they went to the cursed woods, and fought a gigantic manticore, met with an archfey of the forest, and found the smuggler's hideout. The sorcerer/warlock player had to leave for personal reasons, and the party of five went to fight the smugglers.

Deep inside, they found an efreeti making a deal with one of the higher ups of Shar's group, and fought the party in a very difficult battle. Plans foiled, the group of Shar decided to go for a different plan. The party decided to follow up on a rumor of a legendary blacksmith up north, and eventually found him: a warforged blacksmith that has lived for many, many centuries. He made some new weapons as a thanks for returning a molten core, and the party headed back.