do n't think of the three of you sitting together at their hearth ; do n't go back to the glen , not now , not for a long long time ; do n't walk among circles of stone ; do n't visit caves ; do n't succumb to the temptation of mortal beauties who may die at your touch ... . do n't call them , do n't beg to hear a coldness , estrangement , evasion in their voices .