why did sir henry reaturn to the cave?

The cavern was really beautiful and fascinating to Sir Henry but they did not have time to examine it.

strange beasts, and on the sides of the cave were fanlike ivory tracings, such as the ... here and there smaller caves, exactly, Sir Henry said, as chapels open out of ... we had not, however, the time to examine this beautiful cavern,,, we would investigate it thoroughly on our return...