(CNN)"Our story will be that we are newlyweds on our honeymoon," the young woman allegedly wrote.
But in reality, according to a criminal complaint, she and her soon-to-be husband had a far more sinister trip in mind: flying from Mississippi to Europe, then traveling to Syria and joining ISIS.
Now 20-year-old Jaelyn Delshaun Young and 22-year-old Muhammad Oda Dakhlalla are facing federal charges after authorities arrested them at Golden Triangle Regional Airport in Columbus, Mississippi, over the weekend. They're accused of conspiring and attempting to provide material support and resources to ISIS.
Ken Coghlan, an attorney representing Young, declined to comment to reporters outside the federal courthouse in Oxford, Mississippi, after a hearing there Tuesday. Greg Park, a federal public defender representing Dakhlalla, also declined to comment.
An affidavit filed in U.S. District Court details how two undercover FBI employees unraveled the alleged scheme.
<img alt="The ISIS terror threat " class="media__image" src="http://i2.cdn.turner.com/cnnnext/dam/assets/150807113003-01-isis-ramadi-0806-large-169.jpg">
Court documents detail what federal investigators say were the couple's plans to travel to Syria and join ISIS, as allegedly communicated through social media to the undercover FBI employees over the past several months.
Among the allegations:
-- Young wrote of her plans to marry Dakhlalla so the two could travel to Syria together. She confirmed that the wedding took place in June, and said the couple's cover story would be that they were flying to Europe on their honeymoon. To avoid suspicion, "We won't be flying to Istanbul. We will fly to a different country and take a bus."
-- The couple described their skills and asked how they could help the terror group's efforts."I am good with computers, education and media," Dakhlalla allegedly wrote in one message to an FBI employee. "What could I contribute?" Young also allegedly told an undercover FBI agent that her skills would be useful. "I am skilled in math and chemistry and worked at an analytical lab here on my college campus. My partner is very good with things like computer science/media. We learn very fast and would love to help with giving medical aid."
-- In messages detailed in the complaint, the couple seemed enthusiastic, but also concerned about how training would work once they arrived. "Salaam again," Dakhlalla allegedly wrote in a message to an FBI employee. "I wanted to ask about the military experience there. Would I be with people that speak English as well or do they put me with everyone at basic training? I am excited about coming ... but I feel I won't know what all I will be doing."
-- Young allegedly praised the July 16 attacks at military centers in Chattanooga, Tennessee, in which four Marines and a sailor were killed. "The numbers of supporters are growing," she said in a message, according to the complaint.
-- In August, just days before the couple allegedly planned to begin their journey, Young allegedly wrote that it should be easy to make it past security at the Mississippi airport. "We will be flying direct. We live in a small town with a very small (poor) airport that doesn't have much, if any, security. ... That's one U.S. weakness -- small towns' airports have poor funding and less educated staff so it is easier to get through."
-- Last week, the couple allegedly bought plane tickets to fly from Columbus, Mississippi, to Istanbul. Authorities arrested them Saturday at the Mississippi airport, and both "confessed to attempting to travel to Turkey to join ISIS," according to the complaint.
According to a law enforcement official, Dakhlalla is the son of a local imam, Young is the daughter of a Vicksburg, Mississippi, police officer and a recent convert to Islam.
Family members did not immediately respond to a request for comment.
Both are former Mississippi State University students, according to university spokesperson Sid Salter. Dakhlalla, of Starkville, Mississippi, graduated in the spring with a degree in psychology, and Young was last enrolled in the spring as a sophomore studying chemistry.
According to Salter, the university was contacted by MSU Police on Saturday regarding the arrest of the former students at the Golden Triangle Regional Airport.
Dakhlalla and Youngwere denied bond at a hearing Tuesday and remain in the custody of federal marshals, the Justice Department said.