Alice, 7 bytes
\oi /R@ Explanation
\ Reflect to SE. Switch to Ordinal. R Reverse top string on stack, does nothing. Reflect off bottom boundary --> move NE. i Read all input as a single string. Reflect off corner --> move back SW. R Reverse top string on stack, reverses input. Reflect off bottom boundary --> move NW. \ Reflect to S. Switch to Cardinal. / Reflect to NE. Switch to Ordinal. o Print reversed output. Reflect off top boundary --> move SE. @ Terminate the program.