Keep an eye out for mines, which can be reset by picking them up. Half Life 2: Episode One Walkthrough - Half Life-2-Episode-One 101 Debris such as this cinderblock can help defend against the zombies and head crabs.
Half Life 2: Episode One Walkthrough - Half Life-2-Episode-One 100 Once Alyx catches her breath she'll deactivate this force field. Lowlife Half Life 2: Episode One Walkthrough - Half Life-2-Episode-One 99 You can jump to nearby pages of the game using the links above.