Portals allow a creature to travel between two worlds. The manticore, for example, is a creature who has to use a portal to enter this world. Its life source is the Spirit world so it cannot stay away from it for too long. A portal is usually an object of great worth, such as a box with gems on it or a jewel. The dimensions of a portal depend on the creature who uses it: the stronger the magic is, the larger the portal must be. Sometimes a portal can be as small as a necklace. The witchAlice came into possession of a portal through which she summoned a manticore. She thought she would have been able to control it and to harness its power for the good and for healing but it was too strong for her. She became the manticore's slave and poisoned Uther under its control. The spells that Alice and Merlin used to summon the Manticore from the Spirit world are: "Gebiede ic þone feorhberend þære ealdaþ æ" and "Cume her, pin scinnlæcan". Gaius was able to destroy the portal, and thus the manticore as well, with the incantation "Adee þas sawle duru!" (Love in the Time of Dragons).