White/Black piece on e1 is immobilized and commits suicide: @-e1
(the preset wouldn't accept it as move 1, because of comparisons between
this move's parameters and last move's parameters, but Rococo features
no suicide at move 1 anyway)
White Swapper on e1 moves to unoccupied square e2: S e1-e2
White Swapper on e1 trades positions with White/Black piece on e2: S
e1-e2
White Swapper on e1 explodes with Black piece on e2: S e1-e2; @-e2
White Archer on e1 moves to unoccupied square e2: B e1-e2
White Archer on e1 kills Black piece on e2: B e1-e2
I chose B/b (Bowman) for Archers (and later D/d for Birds) and read
Peter's comment only after Michael and Roberto started a game of Fugue,
so I haven't corrected that inconsistency.