I'll own straight up that I am copying and pasting this from the link below, as others have done better write-ups than I ever could:
Frauke Liebs disappeared on June 20th 2006 from the town Paderborn in Germany. Her body was found almost four months later, on October 4th 2006. The circumstances of her disappearance are mysterious, especially since she is believed to have made contact with her friends between her disappearance and her death.
2006 was the year of the football World Cup in Germany. Frauke, a 21 year old nursing student, had met her mom and her flatmate in a restaurant during the afternoon. While she was there, she got a text from a friend and arranged to meet her and some other friends in an Irish Pub in downtown Paderborn to watch some of the games. Her mom dropped her off at the pub around 9 pm. During the Sweden England match she exchanged text messages with an acquaintance, until the battery of her cellphone ran out. She then borrowed the battery of her friend, but the friend said that she returned the battery before leaving. At about 11 pm Frauke said goodbye and headed home. It is assumed that she walked home, because she was said to only have about 5€ on her at this time. Her flat was about 1,5 km (about 1 mile) away from the pub. Nobody knows which path she took, because nobody saw her after she left the pub. Her flatmate Chris claimed that she never arrived at the flat.
At 00:49 am her flatmate received a text from Frauke, which stated that she‘d return later. The police was able to figure out that the text was sent out from the Nieheim-Entrup area. She did not appear at work the following day, and after she was not in the flat, Frauke's mother reported her missing.
Over the next days, Frauke contacted her flatmate five times over the cellphone. The calls were usually short and during the evening hours and did not contain a lot of information about her situation. In the first calls, Frauke hinted that she would come back soon, but answered further questions evasively or mysteriously. The last phone call was received on the evening of June 27th, while Frauke's sister was present. Frauke got asked if she was held against her will, and supposedly said „yes“, but then immediately after „No“ in a louder tone. After that, the contact to Frauke was lost. According to police, during these phonecalls Frauke's cellphone was in various industrial zones of Paderborn. The police also assumes that the calls were placed from within a car that was driven to those areas.
We have transcripts of the texts and phone conversations, translated from German. I'll add them in their own posts, as some can be quite long.