pre 1988 VA assumed loan in foreclosure...TX

This is a foreclosure in Texas and our auction is March 4th so in a bit of a time crunch. This property was bought in 1986 with a VA loan. He sold the house in 1993 and the loan was assumed by the buyer. The buyer then sold the house in 1996. The new buyer assumed the existing loan. So basically this VA loan has been assumed twice. Well this last person has gone MIA (we think she went back to Mexico) and left the house abandoned. CITI has the loan. The original loan holder is still being held responsible for the loan and called me today. How can the original owner take back ownership of the property if we cannot find this woman? Is there some type of redemption law that protects the original VA loan holders in these situations thus delaying the foreclosure and allowing him to take ownership of the property? Anyone know?