diff --git a/spacy/vectors.pyx b/spacy/vectors.pyx
index ac748292c..e569b46e7 100644
--- a/spacy/vectors.pyx
+++ b/spacy/vectors.pyx
@@ -4,16 +4,12 @@ from collections import OrderedDict
 import msgpack
 import msgpack_numpy
 msgpack_numpy.patch()
-from cymem.cymem cimport Pool
 cimport numpy as np
-from libcpp.vector cimport vector
 
 from .typedefs cimport attr_t
 from .strings cimport StringStore
 from . import util
-from ._cfile cimport CFile
-
-MAX_VEC_SIZE = 10000
+from .compat import basestring_
 
 
 cdef class Vectors:
@@ -60,7 +56,21 @@ cdef class Vectors:
         yield from self.data
 
     def __len__(self):
-        return len(self.strings)
+        # TODO: Fix the quadratic behaviour here!
+        return max(self.key2row.values())
+
+    def __contains__(self, key):
+        if isinstance(key, basestring_):
+            key = self.strings[key]
+        return key in self.key2row
+
+    def add_key(self, string, vector=None):
+        key = self.strings.add(string)
+        next_i = len(self) + 1
+        self.keys[next_i] = key
+        self.key2row[key] = next_i
+        if vector is not None:
+            self.data[next_i] = vector
 
     def items(self):
         for i, string in enumerate(self.strings):
@@ -75,9 +85,9 @@ cdef class Vectors:
 
     def to_disk(self, path, **exclude):
         serializers = OrderedDict((
-            ('vectors', lambda p: numpy.save(p.open('wb'), self.data)),
+            ('vectors', lambda p: numpy.save(p.open('wb'), self.data, allow_pickle=False)),
             ('strings.json', self.strings.to_disk),
-            ('keys', lambda p: numpy.save(p.open('wb'), self.keys)),
+            ('keys', lambda p: numpy.save(p.open('wb'), self.keys, allow_pickle=False)),
         ))
         return util.to_disk(path, serializers, exclude)
 
diff --git a/spacy/vocab.pyx b/spacy/vocab.pyx
index 055f2ef24..1fc3f5e39 100644
--- a/spacy/vocab.pyx
+++ b/spacy/vocab.pyx
@@ -19,7 +19,7 @@ from .tokens.token cimport Token
 from .attrs cimport PROB, LANG
 from .structs cimport SerializedLexemeC
 
-from .compat import copy_reg, pickle
+from .compat import copy_reg, pickle, basestring_
 from .lemmatizer import Lemmatizer
 from .attrs import intify_attrs
 from .vectors import Vectors
@@ -244,7 +244,7 @@ cdef class Vocab:
 
     @property
     def vectors_length(self):
-        raise NotImplementedError
+        return len(self.vectors)
 
     def clear_vectors(self):
         """Drop the current vector table. Because all vectors must be the same
@@ -264,7 +264,9 @@ cdef class Vocab:
 
         RAISES: If no vectors data is loaded, ValueError is raised.
         """
-        raise NotImplementedError
+        if isinstance(orth, basestring_):
+            orth = self.strings.add(orth)
+        return self.vectors[orth]
 
     def set_vector(self, orth, vector):
         """Set a vector for a word in the vocabulary.
@@ -274,13 +276,17 @@ cdef class Vocab:
         RETURNS:
             None
         """
-        raise NotImplementedError
+        if not isinstance(orth, basestring_):
+            orth = self.strings[orth]
+        self.vectors.add_key(orth, vector=vector)
 
     def has_vector(self, orth):
         """Check whether a word has a vector. Returns False if no
         vectors have been loaded. Words can be looked up by string
         or int ID."""
-        return False
+        if isinstance(orth, basestring_):
+            orth = self.strings.add(orth)
+        return orth in self.vectors
 
     def to_disk(self, path, **exclude):
         """Save the current state to a directory.