How to get the thieves quests in Tarant ?

I learnt on this site there are several thieves quests in Tarant (underground), but I can't trigger any of them.
What should I do to start at least one ?
My main character alignement is 35 (I was 41 at a certain time, but I dropped down 35 by killing the Elves, stealing the Elven stone and bringing it back to Mrs.Pettibone).
Is it why Thaddeus Mynor refuses to talk to me ?
Is there another reason ?

PS: I'm with Virgil, Magnus and Sogg. I'm human, level 14, slightly "technological".

 

After you have done the Elven Ruin quest for Mrs Pettibone, talk to the guy in the grey suit outside her house. He tells you to go see Thad.

 

If your level is high enough (20 or so?) you also get the Barbarians of Kree quest. It's a tough fight.

 

Also, once you've done Thaddeus' quest and joined the underground, you can get Thieves Guilds quests from pretty much any human walking around the bad side of Tarant.

They hand the quests out 5 (or 6?) at a time. As you complete quests, you can talk to them and get assigned more.

 

If you've killed Lukan however, you can't join the Thieves Underground - if Lukan is dead, you can't trigger the conversation with the guy in Madam Lil's or whoever else tells you to talk to Thaddeus Mynor. There's a couple of people to talk to to get jobs - small lady in train station, guy wandering around docks/low dervish row and there's at least one more person.

 

No you can still get introduced into the Underground even if you killed Lukan. If you do the Cassandra Pettibone quest to steal the tombstone, you can get the invite.

 

It's the painting quest.