Here indeed was an obstacle.

Winnie and Hattie stared at it with blank faces and groaned.
"We'd forgotten the wretched Llanelwyn stream.

What atrocious luck! Don't believe there's the ghost of a bridge anywhere.

Shall we have to go back ?" "I'm not going back," declared Rona sturdily.

"There must be some way of getting over it some where.