Thanks, lilkim, that's a good tip regarding the key.
Hi Joan,
Getting past Marty and his dog for the second time is tricky. Here's the excerpt from the walkthrough:
1. Go out of the office building.
2. Take the bottom of the screen exit and see Holmes standing right of the lamp post.
3. This part requires very precise positioning. Click to get Holmes above and little to the right of the covered wagon at the bottom of the screen. The spot he stands on is below a dark area on the ground.
4. Take the time to open your inventory and move the warehouse key to be easily accessible.
5. Wait until Marty turns the corner and just about even to the covered wagon's tongue (woods); the dog pass the lamp post at top of screen, then run down and cross to the left and up to the door of the Fairfax theatre on the left of the screen. Be fast here.
6. Go close to the door and immediately - use the warehouse key on the lower part of the door.
It took me many attempts the first time I played the game. Good luck, and if you still have problems please let us know.