Isolde’s mother (to make) _has made_a love potion that (to believe)
_is believed__to have a magic effect on a person who (to drink)_drinks__it. The ladies-in-waiting (to entrust) _are_entrusted_with the task of giving the potion to Isolde and the king. The Queen (to believe) _believes_that if that potion (to give) _is given to them, it (to ensure) _will ensure_their happy marriage. But on the voyage to Cornwall the potion mistakenly (to give) __was given__to Tristan and Isolde and they (to fall) fell_passionately in love.