The Iss Ormr Langskip

The Iss Ormr Skeið is fast becoming a notorious long boat from Norway. Its name is translated as: Iss - Ice, Ormr - Dragon, Langskip - Warship. So far the ship and it's crew has raided various small holdings around the British Isles, northern continental Europe, and has penetrated down some of the larger rivers in northern Europe too. The ship is named after Forkhr the Iss-Ormr, the leader of the Viking band that uses the ship.
Or at least used to use the ship. It has recently been found floating on the Rhine river near it's head land. It looks the Vikings had somehow used the mouth of the Rhine at the North Sea to navigate upwards. The crew looks as if the ship had seen an attack that left no bodies behind. A handful of axes, spears, knives & shields are left behind, with some spears. The hold seems to have been broken into, and much of the goods & treasure still remain inside. A few Saxons are also there bound up and to be sold as slaves. They tell a story if spoken to, that the ship was taking on goods at some port they weren't sure off, and a strange elongated wooden box (covered in pictures up a length on top) was brought on board, and two jars with the tops in the shape of cats. Also, a small box was placed on top of the larger box, with what looked like a beetle design on top. It was made of polished black wood. Around the night of a half moon, the larger box started to shudder, and then the top opened. A sandy mist poured out, and swept up to were the crew had been. They heard screaming and then nothing.
After a while the mist (coloured reddish), came down, lifted the items and forced the hold door open. From there it was closed again, and then utter silence. They had been drifting since.