Question: What did Madsen find on his daughter's neck?
About the article "As Long as You Love Me (Justin Bieber song)", section "Synopsis".

Candidate passages:
The video starts off with some flashbacks foreshadowing of what's going to be shown or happen in the video.
Then presently, at a mansion gate, Bieber appears as a loyal-but-troublemaking boyfriend to the daughter of an overprotective father, played by Madsen.
In what can be seen as a prelude to the main events of the video, Madsen finds the words "You r so sexy" written on his daughter's neck.
Outside their house, Madsen threatens Bieber to stay away from his daughter, despite Bieber's insistence that he loves her.
Bieber and his love interest secretly plan to meet at a train station late at night, to escape the clutches of her father.
However, their plans are foiled when Madsen finds his daughter's bedroom empty and races off, only to catch up with them in the middle of the street.
Bieber is assaulted by Madsen multiple times, only to rise to his feet and stand up again as the daughter watches and screams in horror.
As the video fades, representing that Bieber is passing out from the pain, Madsen drags his daughter to their car.
Throughout the video, scenes of Bieber and his love interest in various scenes (such as on her bed, at the park and on a rooftop) are shown, displaying their love.
The video also features a complicated dance routine performed in a parking garage, which is rumored by multiple critics to be a nod to the video for Michael Jackson's "Bad" (coincidentally, Madsen also appeared in the video for Jackson's "You Rock My World").
Thorvald John Marius Madsen (February 18, 1870 in Frederiksberg – April 14, 1957 Gjorslev) was a Danish physician and bacteriologist.
Madsen was the director of Statens Serum Institut from 1910 to 1940.
He was the son of General V. H. O. Madsen.
During World War I, Thorvald Madsen in his capacity as director of Statens Serum Institut was heavily involved in humanitarian work for prisoners of war.
From 1916 onwards Madsen did several inspection visits to detention centers in Russia, where conditions were highly questionable.
During these travels brought Thorvald Madsen, among other things excess serum against various diseases.
In addition, Madsen helped more Danish-Schleswigers, who had been in German military service and ended up a prisoner of war.
Thorvald Madsen was also involved in the work of selecting sick prisoners of war who were sent to Denmark as part of the conditions of prisoner exchanges between, on the one hand, Austria-Hungary and Germany on the other hand, Russia.
In the years 1921-1937 was Thorvald Madsen, president of the League of Nations Health Committee.
The current WHO relies heavily on the Health Commission's work.
Madsen was Knight of the Dannebrog in 1902, Dannebrogsmand 1918, the Commander of the 2nd degree in 1920, of 1 degree in 1927 and received the Grand Cross 1937.
He is buried in Garrison Cemetery. 
Madsen started playing as a junior for Roskilde B 06, before he moved on to the youth team of Brøndby IF.
Considered a good talent, he played 35 matches and scored nine goals for various Danish national youth teams from 1993 to 1999.
He made his senior debut for Brøndby in April 1997, and went on to win three Danish Superliga championships and the 1998 Danish Cup in his six years with the club.
He finished the 2001–02 season as joint league top scorer with Kaspar Dalgas, and Madsen made his debut for the Danish senior national team in October 2001.
He was included for the Danish team to compete at the 2002 FIFA World Cup, but did not play any games at the tournament.
Madsen was long linked with a move abroad, and he was eventually loaned out to German team VfL Wolfsburg in January 2003, playing in the top-flight Bundesliga championship.
A part of the loan contract was a June 2003 transfer deal worth 15 million DKK, but as Wolfsburg eventually rejected the transfer, Madsen ended up playing for German league rivals VfL Bochum in the summer 2003.
In his first season with Bochum, Madsen scored 13 league goals, and he was chosen to represent the Danish national team at the 2004 European Championship, where he took part in a single match at his second international tournament.
Following Euro 2004, Madsen scored his first national team goals, when he scored three goals in a 5–1 win against Poland in August 2004.
As Bochum were relegated following the 2004–05 season, Madsen moved on to 1.
FC Köln in July 2005.
Never a success at Köln, he was told to find a new club in January 2006.
On 30 January 2006, he signed a loan deal with English club Southampton FC, lasting until the end of the 2005–06 season.
Madsen scored twice in his nine league games for Southampton in his loan spell, before returning to Köln, who had then been relegated to the 2.
Bundesliga.
He played 13 games for Köln in the 2nd Bundesliga before leaving the club.
In May 2007, he agreed a move back to Brøndby IF, signing a five-year contract effective from 1 July 2007. 
Valhalla would become the major breakthrough for illustrator Peter Madsen, who has developed greatly during his work on the series.
Apart from doing the art for all the albums, he has been a co-writer for most of them.
By far the most high-profile member of the creative team, the series is often referred to as "Peter Madsen's Valhalla".
Hans Rancke-Madsen has been the major writer of the series, together with Peter and other co-writers Per Vadmand and Henning Kure.
Rancke-Madsen has written for all albums but eleven and twelve, but will return for the thirteenth album.
The colouring has always been a great part of the art of Valhalla.
The first eight albums were coloured by Søren Håkonsson.
Peter Madsen did the colours himself for the ninth album, while albums ten to twelve were done by Jesper Ejsing.
Håkonsson returned for the thirteenth album, where he did half the pages, the other half being done by Madsen. 
Madsen was married to his wife Midori.