Title issue, need some advise

[Shane Allman]

I purchased my first investment property in the end of Summer.   This was a Fannie Mae repo with a hitch.  This property that was foreclosed on only included 2 of the 4 lots.  After locking down the house, I tracked down the heirs of the former owners (2 surviving siblings) and they were wiling to sell the 2 additional lots.  In handling all the heirships, we discovered one of the deceased siblings had a son and the Title company required his signature to close.  I contacted him and he said "not a problem, send me the paperwork".  ( we are only talking about $1000 for the pair of lots , 50x50 lots).  Now he will not sign, he won't respond to text or emails.  He has cut off all communication.  He had not talked to the living siblings in over 12 years.   I have offered to pay him, pay for the notary, send a mobile notary, etc.... with no response.    My house reno is done and I just need this one signature to move forward with listing/ selling.  Any suggestions.   This is in Texas.  

[Wayne Brooks]

@Shane Allman 
Did the Original mortgage document encumber all 4 lots, or only the 2 that were foreclosed on?

I assume only the 2 lots were included in the purchase contract and mls listing legal description?