In Baldur's Gate II: Shadows of Amn and Baldur's Gate II: Throne of Bhaal, Saemon Havarian is a flamboyant and opportunistic sea-captain and corsair with a knack for getting out of trouble, often by putting others in it in his stead. He will take the protagonist's party to Brynnlaw near Spellhold, regardless of whether his aid is acquired through the Shadow Thieves or Bodhi. It will shortly turn out that Havarian has betrayed the party when he leads them into a vampire ambush. He's actually working for Irenicus more or less against his will. After the player's party escapes from the maze under Spellhold, he appears again with a plan to defeat Irenicus, ultimately forcing the mage to flee.
Havarian offers to take the party to where Irenicus is going, but if they choose to take up on his offer it turns out he no longer has a ship and they have to steal one for him from the Pirate King, as well as do his fighting for him when the pirates catch up with them. As they set out Havarian "gifts" the party with a blade of an unknown magical weapon he was given by Irenicus. It actually belongs to a Silver Sword, a holy item of the githyanki, who soon catch up with the ship in a levitating craft of their own. Havarian tries to implicate the player character's party for the theft of the blade, but the githyanki, led by Simyaz, decide everyone onboard is guilty by association and attack. The battle is interrupted by an attack of the sahuagin. The githyanki evacuate and Havarian teleports away while his ship sinks along with everyone still on it, the player's party being captured alive by the sahuagin.
Later on, the player character may have the chance to ask Aran Linvail to hunt down Havarian for revenge, but to no avail.
In Baldur's Gate II: Throne of Bhaal Havarian is encountered again in Amkethran, where he's in trouble with a couple of dim-witted thugs who demand back their possessions. Upon seeing the player character, he immediately lies that they have the missing items and vanishes with his usual "better you than me" apology while the thugs attack them. His aid needs to be enlisted later on, however. Havarian has managed to make himself quite the reputation locally as a daring thief, operating from a secret base in the city, and can help the player character inside the monastery to confront Balthazar.
Ways to kill Saemon Havarian: 1) In Baldur's Gate II: Shadows of Amn, when the player's party is attacked by githyanki, there's chance to chop Saemon Havarian into pieces before he teleports away. However, the text before entering the sahuagin city will still say he fled. Later in the conversation with Aran Linvail the player can say that he/she has already killed Saemon. However, this kill will not prevent Saemon from appearing again in Baldur's Gate II: Throne of Bhaal. 2) When the player sees Saemon the first time in Amkethran, although he will immediately flee, a Spell Sequencer or Spell Trigger packed with powerful damaging spells like Skull Trap or Sunfire can still kill him before he's able to teleport away. This way, when the player sees Elminster after defeating Sendai and Abazigal, he will inform the player that Saemon is killed and suggests that the player seek out the innkeeper in Amkethran for help in order to confront Balthazar. 3) He will be in his secret base after Elminster tells the player to seek him for help to confront Balthazar. Then the player can kill, or disable him with spells such as Imprisonment, Flesh to Stone or Feeblemind.