This was really two separate trips with slightly different personnel.
The initial trip is a re-exploration of the lodge of Hakkar the Swift (see A6).
The next trip takes place on the eve of Grettir’s wedding to Kisten the middle daughter of Yithmak the White, Lord of Sequarl. At his betrothal, Grettir had been presented with heirlooms traditionally held by the heir. One of these turns out to be the magical key to a secret and forgotten Dungeon beneath the Great Black Rock Keep of Sequarl. With hours to go before the wedding, Grettir thinks it is a good idea to lead a party into this secret dungeon. There is some consternation in the castle when there is no sign of the groom on the morning of the wedding. However, Grettir does show up, looking only a little dishevelled, just in time for his nuptuals and all is well.
Ref A16a
OE Date: Summer 676
Characters: Grettir, Nickar, Eggo, Aradan, Silden, Marna, Salrod, Shizarem, Gerindar, Alberic. NPCs: Yog, Eargh Skolson, Kisten
Real World: When – New Year 1981 ; Where – St Andrews (Gatty)