Wasteland Knight
Adventurer
I'm looking for ideas to flesh out the evil plot of an NPC in my game. A plot I didn't even realize was brewing until after events were set into motion 
Here's the backstory: I needed to get the party from City A to City B for the next adventure. The hook in City B was helping an orphanage find (and rescue) some kidnapped orphans (Shackled City). While this backstory could tug at the heartstrings of many a good-aligned party, the PCs in my game are far more morally ambiguous and mercenary inclined than the average published adventure assumes.
So, having done various "odd" jobs in City A for those with power and ready cash but a strong desire to maintain clean hands, I came up with a hook to the hook. The party was hired by a wealthy (and connected) merchant-lord named Keltos. My quick backstory in my notes was this:
"Keltos is a wealthy merchant and trader of City A. He became a parent late in life, and his wife died in childbirth. Several years ago his daughter, Elena, ran off with a scoundrel and was never heard from again.
Keltos has recently discovered his daughter died (abandoned by her husband) but had a daughter. Keltos’ granddaughter was an orphan in City B. Party is hired to fetch his granddaughter from the Orphanage in City B, as Keltos wants this done quickly, quietly and discretely. The roads have been more dangerous of late, so hiring men both skilled with the blade (or spell) and ready to make use of these skills at a moment's notice is desireable"
Being offered very nice compensation for what seemed like low risk work, the party accepts ("low risk, high reward" is one of their mottos). When they arrive in City B, they discover the girl they sought was kidnapped, along with three other children. This ties in with the actual plot of the published adventure.
This brings me to the current situation. The party seems to think this story is pretty thin and there MUST be a real reason behind this fellow Keltos suddenly deciding to be reunited with his granddaughter. And if they were to go missing, any compelling evidence tying Keltos to the girl in the orphanage would be gone. So when they stated their concerns, I responded with "well, anything's possible." , but in my head I'm thinking "yeah, something DOES seem fishy with this story".
So, having (subconsciously) created a nefarious plot, I need to flesh it out. Why does this fellow REALLY want his daughter? And how with the almost certain double-cross against the party play out?

Here's the backstory: I needed to get the party from City A to City B for the next adventure. The hook in City B was helping an orphanage find (and rescue) some kidnapped orphans (Shackled City). While this backstory could tug at the heartstrings of many a good-aligned party, the PCs in my game are far more morally ambiguous and mercenary inclined than the average published adventure assumes.
So, having done various "odd" jobs in City A for those with power and ready cash but a strong desire to maintain clean hands, I came up with a hook to the hook. The party was hired by a wealthy (and connected) merchant-lord named Keltos. My quick backstory in my notes was this:
"Keltos is a wealthy merchant and trader of City A. He became a parent late in life, and his wife died in childbirth. Several years ago his daughter, Elena, ran off with a scoundrel and was never heard from again.
Keltos has recently discovered his daughter died (abandoned by her husband) but had a daughter. Keltos’ granddaughter was an orphan in City B. Party is hired to fetch his granddaughter from the Orphanage in City B, as Keltos wants this done quickly, quietly and discretely. The roads have been more dangerous of late, so hiring men both skilled with the blade (or spell) and ready to make use of these skills at a moment's notice is desireable"
Being offered very nice compensation for what seemed like low risk work, the party accepts ("low risk, high reward" is one of their mottos). When they arrive in City B, they discover the girl they sought was kidnapped, along with three other children. This ties in with the actual plot of the published adventure.
This brings me to the current situation. The party seems to think this story is pretty thin and there MUST be a real reason behind this fellow Keltos suddenly deciding to be reunited with his granddaughter. And if they were to go missing, any compelling evidence tying Keltos to the girl in the orphanage would be gone. So when they stated their concerns, I responded with "well, anything's possible." , but in my head I'm thinking "yeah, something DOES seem fishy with this story".
So, having (subconsciously) created a nefarious plot, I need to flesh it out. Why does this fellow REALLY want his daughter? And how with the almost certain double-cross against the party play out?