Layton receives a letter from professor Desmond Sycamore, who requests his help in solving a mystery he has stumbled upon: the identity of a young girl who was frozen in ice for millions of years but is inexplicably still alive.
It is also, according to Word of God, the final game in the series to feature Layton himself though not the last game overall. The sixth game in the Professor Layton series, third in the prequel series.