esfuminarse

= disappear into + the blue, vanish into + the blue.

Ex. We're all puzzled by the mystery of the Bermuda Triangle where hundreds of boats and planes have disappeared into the blue leaving no trace at all.

Ex. All about the plane round puffs of white smoke suddenly appeared, broke, and vanished into the blue.

* * *

= disappear into + the blue, vanish into + the blue.

Ex: We're all puzzled by the mystery of the Bermuda Triangle where hundreds of boats and planes have disappeared into the blue leaving no trace at all.

Ex: All about the plane round puffs of white smoke suddenly appeared, broke, and vanished into the blue.