Timothy brooded a few minutes then attempted the charm again. He closed his eyes tapped and swirled the wand and..."Riveerto".....the doorknob spun around and came to a stop, appearing to be his old closed pocketwatch, he grinned at the professor and opened it triumphantly.

There was a keyhole where the watch face should be.

Crap

So he tried it again, invisioning what it should look like deep within his thoughts.

"Riverto!"

It spun again, this time looking much akin to its last transformation, and he hurried to open it before declaring his victory. Yet...it was stuck.....

He pried it apart and it was the normal watchface, ticking away cheerfully. He had done it....he was not too proud of himself though....and only through a trail of failures did he actually get to the destination.