Help Portal

Syntax cast 'portal' <target>

The portal spell is similar to gate, but creates a lasting one-way
portal to the target creature, instead of transporting the caster.
Portals are entered using 'enter'  command, as in 'enter portal'.
Portals cannot be made to certain destinations, nor used to escape
from gate-proof rooms.  Portal requires a special source of power
to be used, unfortunately the secret of this material component
has been lost...

See also nexus, teleport, gate, portal, refresh portal