'Stösser' was a German airborne undertaking, otherwise known as 'Hohes Venn' and part of the 'Greif' (iv) component of 'Wacht am Rhein', into the US rear area at Bell Croix Jalhay in the High Fens area during 'Wacht am Rhein' with the object of taking crossroads of the N-68 and N-672 highways and holding them until the arrival of the 12^th SS Panzerdivision 'Hitlerjugend' (15/16 December 1944).

Both the targeted roads were main supply routes, the N-68 from Eupen and the N-672 from Verviers meeting at Belle Croix Jalhay and providing access to either Malmédy or Elsenborn. The operation was commanded by Oberst Freiherr Friedrich August Freiherr von der Heydte, who was allocated just eight days in which to prepare the mission. The majority of the paratroopers and pilots assigned to the operation were undertrained and inexperienced, and while the Kampfgruppe 'von der Heydte' occupied a position at Porfays in the forest to the east of the N-68 and conducted some local skirmishes against small US convoys, even taking a few men prisoner, the undertaking was a failure.

von der Heydte, an experienced paratroop commander and veteran of the 'Merkur' airborne assault on Crete in 1941, was ordered on 8 December to prepare, within eight days, for a mission of which no details were vouchsafed to him. von der Heydte wished to use his own regiment, but this was forbidden because its movement might alert the Allies to the impending counterattack. Instead, he was provided with a Kampfgruppe of 800 men that was to be created by Generalleutnant Eugen Meindl’s II Fallschirmkorps by drawing 100 men from eight of the corps' regiments. However, rather than contributing their best men as ordered, the regiments sent their misfits and troublemakers. von der Heydte could not afford to resist this too strongly: a cousin of Oberst Claus von Stauffenberg, a central figure in the attempt of 20 July 1944 to assassinate Adolf Hitler, he was already under severe scrutiny. In loyalty to their commander, 150 men of von der Heydte’s own unit, the 6^th Fallschirmjägerregiment, disobeyed orders and joined him.

To avoid alerting the Allied forces, the German command planned to conduct the drop without first conducting reconnaissance or taking aerial photographs.

The men of the Kampgruppe 'von der Heydte' had little time to establish any realistic form of unit cohesion or even to train together, and many of the men had never jumped out of an aeroplane before this undertaking. von der Heydte later commented that 'Never in my entire career had I been in command of a unit with less fighting spirit.' 

On 13 December, von der Heydte visited the headquarters of Generalfeldmarschall Walter Model’s Heeresgruppe 'B' near Bad Münstereifel to complain that the resources allocated to him for the operation were wholly inadequate. Model had already tried to persuade Hitler to attempt a less ambitious counterattack, and told von der Heydte that gave the entire 'Wacht am Rhein' offensive a less tan 10% chance of succeeding, and told him that it was necessary to make the attempt: 'It must be done because this offensive is the last chance to conclude the war favourably.'

The drop was delayed for one day when the aircraft assigned to the operation did not arrive. The revised drop time was 03.00 on 17 December, and the drop zone was 7 miles (11 km) to the north of Malmédy Once landed and assembled, the paratroopers were to take the crossroads and hold it for about 24 hours until relieved by SS-Brigadeführer Hugo Kraas’s 12^th SS Panzerdivision 'Hitlerjugend', hampering the movement of Allied reinforcements and supplies in the area.

Just after midnight on 17 December, 112 Junkers Ju 52/3m transport aircraft, carrying about 1,300 paratroops, took off in conditions characterised by a severe snow storm with strong winds and thick low-level cloud. The Luftwaffe was short of experienced pilots: thus many of the pilots had never flown the Ju 52/3m before, half had never flown in combat, and most were untrained in night drops and even in formation flying. Pathfinder aircraft of Major Kurt Dahlmann’s Nachtschlachtgruppe 20 were supposed to lead the way, but the pilots were so inexperienced that they flew with their navigation lights illuminated. 

Many of the aircraft went off course. Some 250 men were dropped near Bonn, 50 miles (80 km) from the intended drop zone, and some of the aircraft landed without dropping their troops. Strong winds dispersed many paratroops whose aircraft were relatively close to the intended drop zone and made their landings far rougher, and only a small minority of the force landed near the intended drop zone. Since many of the German paratroopers were very inexperienced, some were crippled on landing and died where they fell. Some of their bodies were discovered during the following spring after the snow had melted.

The very wide dispersal of the drop was reflected in the fact that reports of paratrooper landings in location all over the Ardennes, and this initially persuaded the Allies that a large division-sized assault was in progress, causing the US forces much confusion and convincing them to allocate men to secure the rear instead of facing the main German thrust at the front. The entire 3,000-man US 18^th Infantry, together with one armoured combat command of 300 tanks and 2,000 men, searched several days for the German force.

By 12.00 on 17 December, von der Heydte’s unit had completed a reconnaissance of the woods and assembled a total of about 300 men. With only enough ammunition for a single firefight, the force was too small to take the crossroads on its own. von der Heydte first planned to await the arrival of the 12^th SS Panzerdivision to seize the targeted crossroads just before the armour’s arrival. Unable to best the Americans in the Battle of Elsenborn Ridge, the 12^th SS Panzerdivision never arrived. After three days of waiting, von der Heydte abandoned this revised plan and instead converted his mission to a reconnaissance undertaking. SS-Oberstgruppenführer 'Sepp' Dietrich, commander of the 6^th SS Panzerarmee, had laughed at von der Heydte’s request for carrier pigeons, which might have been useful given the fact that none of the paratroopers' radios survived the drop, so he was unable to report the detailed information he gathered.

With only a single day’s food supply and limited water, on 19 December von der Heydte withdrew his force toward the German lines. He used the paratroopers' limited ammunition to attack the rear of the US lines. Only about one-third of the men reached the German rear, and wounded, frostbitten and suffering from pneumonia, von der Heydte knocked on doors in Monschau until he found a German family. The next morning he sent a boy with a surrender note to the Allies, who took him prisoner on 23 December.