Above level 20 Wilderness, you will lose your clue scroll (or casket!), and it will disappear, if it is not among your protected items. Similar to other untradeable items, they are meant to turn into coins; however, as they have a value of zero, they simply disappear. When doing a hard clue involving a Zamorak wizard encounter, this is easy to avoid, as you only need 3 items: a weapon (slashing if you need to cut a web), the clue scroll, and spade. If you bring more than 3/4 items and are attacked by a PKer, you should quickly drop items that you don't care about compared to the clue scroll (such as the spade).
Zamorak wizards are substantially weaker than Saradomin wizards. Zamorak wizards are not poisonous, have low health, low defence (except against Magic), and attack exclusively with Magic (using Flames of Zamorak). As such, activating Protect from Magic completely negates their damage. Since they have very little Defence, melee and Ranged are both effective in dispatching them. If you use Ranged, it is advisable to use a Crystal bow or Toxic blowpipe as they require no carried ammunition that would protect over the clue scroll. Magic, even a Trident, is not advised as they are resistant due to their high Magic level.
Item Quantity Rarity GE market price Bones 1 Always 73
Item Quantity Rarity GE market price Air battlestaff 1 Uncommon 9,032 Earth battlestaff 1 Uncommon 9,032 Fire battlestaff 1 Uncommon 9,055 Water battlestaff 1 Uncommon 9,035 Zamorak monk bottom 1 Uncommon 1,593 Zamorak monk top 1 Uncommon 647
Item Quantity Rarity GE market price Air rune 60; 189; 192 Common 300–960 Earth rune 79; 86; 107 Common 395–535 Fire rune 51; 180; 189 Common 255–945 Water rune 86; 107; 146 Common 430–730 Blood rune 8 Uncommon 2,280 Cosmic rune 25 Uncommon 4,225 Death rune 45 Uncommon 11,205 Law rune 9 Uncommon 2,394 Nature rune 12; 28 Uncommon 3,036–7,084